ADHD - Attention-deficit hyperactivity disorder is a complex medical condition characterized by excessive inattentiveness, impulsiveness and/or hyperactivity as well as difficulty managing emotions and self-regulating action involving executive functions. It is a chronic life-long condition that significantly interferes with everyday life.
Allele (en) - One member of a pair (or any of the series) of genes occupying a specific spot on a chromosome (called locus) that controls the same trait.
Amnion (en) - A thin membrane that surrounds the fetus during pregnancy. The amnion is the inner of the two fetal membranes (the chorion is the outer one), and it contains the amniotic fluid.
AMPA receptor - A transmembrane receptor for glutamate that mediates fast synaptic transmission in the central nervous system. Its name is derived from its ability to be activated by the artificial glutamate analog AMPA.
Anticipation (en) - The change in phenotype of inherited diseases to appear at earlier age of onset and with increasing severity in successive generations. Anticipation is common in trinucleotide repeat disorders such as Huntington's disease and fragile X syndrome.
Association (en) - The common occurrence of certain alleles with a specific character. Contrary to liaison, the association characterizes the link between alleles whereas the liaison characterizes the relation between several loci. In a population of individuals the analysis of the occurrence frequency for certain alleles (diseased subjects and healthy controls) can provide evidence for the pathogenic effect of a specific allele.
Ataxia - Lack of coordination of muscle movements, especially at the extremities. See FXTAS
Base (en) - Shortened version of nitrogenous base, the building blocks of nucleic acid molecules (A – adenine; T – thymine; G – guanine; C – cytosine; U – uracil)
Base pair - Two complementary nucleotide bases in DNA (A with T; G with C).
Blastula / Blastocyst - The blastula is a hollow sphere of cells formed during an early stage of embryonic development (in human beings around the fourth day after fertilization). The following step is called Blastocyst.
Candidate Gene - see Gene
Carrier / Pre-mutation carrier - Men and women can be carriers of a Fragile X mutation. A carrier is an individual who carries an altered form of a gene which can lead to having a child or offspring in future generations with a genetic disorder.
cDNA - Complementary DNA (cDNA) which translate back in DNA the messenger RNA (mRNA) template of a gene. A classification as complete as possible of the cDNA of different tissues at various healthy or deviating development steps provides a good indicator on the genes that are playing a role in these biological processes.
Cerebellar Peduncle - A large bundle of projection fibers connecting between cerebellum and the other parts of the central nervous system. Three pairs of cerebellar peduncles conduct this communication : the inferior peduncles - the middle peduncles - the superior peduncles.
Chorial villosities biopsy / sampling - Chorial villosities sampling consist in a biopsy of the trophoblastic (see Trophoblast) cells during the end of the first quarter of prenancy at the level of the chrorion before the latter becomes the placenta. Through a chorial biopsy most frequent chromosome abnormalities can be detected. To avoid complications this biopsy should not take place before 12 weeks long amenorrhea.
Chorion (en) - The chorion is the outer fetal membrane that is sometimes growing from the external membrane of the blastula.
Chromosome (en) - A threadlike structure appearing in a cell nucleus consisting of genes necessary for the transmission of hereditary characteristics. In the human species there are 23 pairs of chromosomes.
Clone (en) - A clone is a group of unicellular organisms (bacteria, yeasts, vertebrates) derived from a common parent cell. In molecular biology : a defined fragment of the genome that is reproduced in a specific manner in cells (cloned).
Cloning - To identify and reproduce particular genomic regions. This can be achieved by isolation of the genomic domain into a vector (see item) followed by the multiple reproduction of this vector. The reproduction of interesting DNA by PCR (see item) is also possible and the consecutive isolation and reproduction in a vector.
Cytogenetic analysis - The study and analysis of chromosomes, their structure, function and abnormalities.
Deletion (en) - A deletion is a mutation in which a part of a chromosome or a DNA sequence is missing. An interstitial deletion occurs from the interior of a chromosome whilst a terminal deletion occurs towards the end of a chromosome.
Dendrites (en) - Dendrites are thin structures that arise from the cell body, often extending for hundreds of micrometres and branching multiple times, giving rise to a complex 'dendritic tree'. They conduct the electrochemical stimulation received from other neural cells to the cell body of the neuron from which the dendrites project.
Disomy , Uniparental Disomy (UPD) - A chromosome or part of a chromosome (partial disomy) is inherited in two copies from only one parent, the corresponding chromosome of the other parent is lost. This can lead to a condition when a printed gene is located on the chromosome.
DNA (en) - Desoxyribonucleic acid. Carrier of the hereditary information in the cell. DNA consists of four bases : Adenine (A), Thymine (T), Guanine (G) and Cytosine ( C ) that are paired (A + T, C + G) and form two spiralling strands through their complementarity : each type of nucleobase on one strand normally interacts with just one type of nucleobase on the other strand.
DNA chips - A DNA micro-array (also commonly known as gene chip, DNA chip, or biochip) is a collection of microscopic DNA spots attached to a solid surface. Through hybridization with DNA strands of different origins, the DNA chips will allow in a near future to analyze several thousands of genes or markers in a single work step.
DNA Methylation - A chemical process in the body that is used to turn chromosome information off or on. In people with Fragile X syndrome, it is this process of methylation that causes the condition by turning genetic information ‘off’, sometimes known as ‘silencing’, where the expression of the gene is silenced.
Double jointed - 'Double-Jointed' means hypermobile : people with more than normal flexibility of their joints are considered to have hypermobility — which simply means their joints (and surrounding structures, including ligaments and tendons) are able to bend farther than average.
Echolalia - Echolalia is the automatic repetition of latest pronounced words or vocalizations made by another person.
Exon (en) - An exon is a nucleic acid sequence in a gene that can be translated in a protein. A gene can consist of dozens of exons separated by introns on a chromosome.
Fibromyalgia - Fibromyalgia is a complex syndrome in which a person has long-term, body-wide pain and tenderness in the joints, muscles, tendons, and other soft tissues. Fibromyalgia has also been linked to fatigue, sleep problems, headaches, depression, and anxiety.
Flat feet - Absence of an arch in the sole of the foot that causes the foot to lie flat when the person is standing. All babies have flat feet because their arches are not yet built up (and their feet tend to be plump).
Fluorescence in situ hybridization (FISH) - A procedure that allows researchers to locate the positions of specific DNA sequences on chromosomes. FISH uses fluorescent probes that bind to only those parts of the chromosome with which they show a high degree of sequence similarity. FISH is often used for finding specific features in DNA for use in genetic counselling, medicine, and species identification. FISH can also be used to detect and localize specific mRNAs within tissue samples.
FMR-1 Gene - The gene associated with fragile X syndrome. FMR (Mental Retardation linked to Fragile X) is the name of the gene characterized by numerous repeats of single trinucleotide sequences on the fragile part of X chromosome. The gene named FMR-1, since there is a second gene - logically named FMR-2 - that is also located on a fragile site with numerous repeats of trinucleotides and is also related to genetically transmitted development retardation. However mutation in FMR-2 are by far less frequent. The information for the synthesis of FMR-1 protein (FMRP) is contained in the binding of the four bases in FMR-1 gene. Strong amplification of the sequence of unstable trinucleotide repeats (CGG) or other mutations turn off FMR-1 gene expression into FMRP. Which means that the genetic information of FMR-1 gene cannot be translated in FMRP protein. Fragile X syndrome is caused by the absence of FMRP.
Fragile-X Syndrome - Fragile X Syndrome (FXS) represents the most common inherited cause of intellectual disability and autism, affecting approximately 1 in 4,000 to 8,000 individuals in the general population. About two-thirds of individuals with FXS have a form of autism spectrum disorder. FXS affects the X chromosome, specifically on the FMR1 gene; therefore, more males are diagnosed with FXS than females. Diagnosis of FXS is made through a DNA (blood) test.
FRMP: Fragile X Mental Retardation Protein - Fragile X mental retardation is caused by absence of the RNA-binding protein fragile X mental retardation protein (FMRP), encoded by the FMR-1 gene. The FMRP binds RNA and influences the translation of RNA into protein, among others in the nervous cells of the brain. RNA present in various components of the neurons, in particular in metabotropic glutamate receptors, are also part of the RNA closely linked to FMRP.
Full Mutation - A mutation in the FMR1 gene with 200 or more CGG repeats.
FXPOI (en) - (Fragile X-associated primary ovarian insufficiency) A condition affecting ovarian function that can lead to infertility and early menopause. It occurs in some female carriers who have a premutation in their FMR-1 gene.
FXTAS= Fragiles-X-Tremor-Ataxia-Syndrom - FXTAS (Fragile X–associated tremor/ataxia syndrome) An adult onset (over 50 years of age) neurological condition, more common and more severe in males, that causes tremor, memory difficulties and balance problems in those with a premutation of the FMR-1 gene. Fragile X–associated tremor/ataxia syndrome (FXTAS) is an “adult onset” neurodegenerative disorder, usually affecting males over 50 years of age. Involving progressively severe “Intention” or “action” tremor (trembling hands and head), difficulty with walking and balance, called “ataxia”, which might result in occasional or frequent falls, cognitive/intellectual decline, FXTAS appears to specifically affect some older premutation carriers, generally grandfathers of children with fragile X syndrome.
GABA neurotransmitter - Gamma-AminoButyric Acid is the major excitatory neurotransmitter in many regions of the brain before the maturation of glutamatergic synapses. It plays a role in regulating neuronal excitability throughout the nervous system. In humans, GABA is also directly responsible for the regulation of muscle tone.
Gene - The unit of inheritance, consisting of a sequence of DNA. The DNA segment which contains information for synthesis of a protein. The candidate gene approach is used in a locatable region of genomic sequence, whose biological properties (functioning, expression modus, etc…) show a correlation with the clinical expression of a carrier gene for a still unknown and not located disease. A candidate gene is also identified by deletion or other mutation with patients.
Gene expression - The extent to which the effects of a gene are manifested. The transmission of the hereditary information from the information sequence contained in DNA to messenger RNA (mRNA) by transcription, and by translation of messenger RNA (mRNA) into a protein. Each of these reactions is subject to a complicated process producing a gene expression specific to the cell and causing in turn a risk for transcription mistake.
Gene mapping - A genetic map that shows the position of the various loci in the human genome, in particular for genes or polymorphisms.
Gene therapy - The treatment of a disease by the introduction of a gene into existing cells, to directly cure the disease (e.g. expression of bleeding reducing Factor VIII in Haemophilia A, expression of the gene product of cystic fibrosis) or to reduce or cure the symptoms of the disease (e.g. erythropoietin expression for chronic kidney disease or dialysis). An infinity of strategies currently exist in experimental research with up to now small but real results.
Genetic counselling - The provision of genetic information to facilitate informed decision-making.
Genetics - The study of inheritance patterns based on transmission of genes from parent to offspring.
Genome - The genome is the entirety of an organism's hereditary information encoded in DNA. The genome is the entirety of an organism's hereditary information encoded in DNA. The human genome is estimated to contain 3 billion base pairs spread over 23 chromosomes and appearing twice each due to the duplication of the chromosome number. The number of human genes is estimated between 50,000–100,000 units. From 30% to 50% of the human genome is composed with repetitive DNA which represents the main problem when physically mapping the genome. The Escherichia coli bacterium is composed with 4.6 million base pairs (in 1996 the sequencing revealed about 4,600 genes). Saccharomyces cerevisiae brewer's yeast contents about 12 million base pairs (in 1996 the complete sequencing revealed about 6,000 genes) whilst Caenorhabditis elegans nematode (roundworm) genome sequence is approximately 80 million base pairs long (in 1998 the complete sequencing revealed about 19,000 genes). The genome of the vinegar fly (Drosophila melanogaster) is about 160 million base pairs long spread over 13,600 genes.
Genome mapping - The genetic recombination frequency observed between two markers is used to determine the location of and relative distances between genes on the chromosome.
Genotype - The genetic constitution of an organism is referred to as its genotype. The genotype is the genetic makeup of a cell, an organism, or an individual (i.e. the specific allele makeup of the individual) usually with reference to a specific character under consideration. A genotype typically implies a measurement of how an individual differs or is specialized within a group of individuals or a species.
Gray-zone alleles or expansions (45-54 CGG repeats) - In the gray zone, there can be more subtle increases in FMR1 mRNA levels up to almost 1.5 times normal when compared with controls. Clinical studies have shown that FXPOI (see FXPOI - primary ovarian insufficiency) occurs twice as often in women who carried alleles in the gray zone compared with general population.
Healthy carrier - An asymptomatic carrier of a mutation at an allele of a gene (=heterozygote). In these cases the mutation at an allele is not sufficient to display symptoms. In the autosomal recessive inheritance patterns clinical symptoms only appear if the second allele is also mutated.
Heterogeneity - The occurrence of similar symptoms of a phenotype coming from different genetic causes (heterogeneous).
Heterozygosity - The presence of different alleles of the same polymorphism or the same gene in an organism.
High-arched Palate - A high roof of the mouth.
Homozygosity - The presence in an organism of the same allele of a polymorph marker. A strong homozygosity (or reduced heterozygosity) characterizes populations with a fewer number of ancestors (Founder-Effect). The reduced genetic variety in isolated populations builds a target group for research on genetically inherited properties with bigger heterogeneity (e.g. Finland, Iceland).
Horseback Riding - see 'therapy'
Hyperacusis (also spelled hyperacousis) - A health condition characterized by an over-sensitivity to certain frequency ranges of sound (a collapsed tolerance to usual environmental sound). A person with severe hyperacusis has difficulty tolerating everyday sounds, some of which may seem unpleasantly or painfully loud to that person but not to others.
Hypertension (en) - Hypertension or high blood pressure is a chronic medical condition in which the blood pressure in the arteries is elevated. This requires the heart to work harder than normal to circulate blood through the blood vessels. Hypertension is a major risk factor for heart attacks, heart failure, peripheral arterial disease and is a cause of chronic kidney disease. Even moderate elevation of arterial blood pressure is associated with a shortened life expectancy.
Hypertonia, muscular - Increased activity and resistance in muscles.
Hypothyroidism - Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone. Early symptoms are : cold intolerance, increased sensitivity to cold, constipation, weight gain and water retention, bradycardia (low heart rate – fewer than sixty beats per minute), fatigue, decreased sweating, muscle cramps and joint pain, dry skin, brittle fingernails, rapid thoughts, depression, poor muscle tone (muscle hypotonia).
Hypotonia - Hypotonia is a state of low muscle tone (the amount of tension or resistance to stretch in a muscle), often involving reduced muscle strength.
Inheritance - A trait or a condition are as well determined by genetic or environmental influences. Heredity may be characterized by different alleles of a gene or by the effect of multiple genes together and also by a certain predisposition to environmental influences (genetic susceptibility).
Inheritance patterns - Inheritance patterns trace the transmission of genetically encoded traits, conditions or diseases to offspring.
Intron (en) - An intron is any nucleotide sequence within a gene that carries no information which can be translated into protein.
Karyotype - Karyotypes describe the number of chromosomes, and what they look like under a light microscope. Attention is paid to their length, the position of the centromeres, banding pattern, any differences between the sex chromosomes, and any other physical characteristics. The preparation and study of karyotypes is part of cytogenetics.
Limbic system - A complex set of brain structures that lies on both sides of the thalamus, right under the cerebrum. It supports a variety of functions, including emotion, behaviour, motivation, long-term memory, and olfaction.
Locus (plural loci) - A position in the genome defined by mutations, a specific location of a gene or DNA sequence on a chromosome. In the structure of a chromosome the genes are linearly organized and each gene sits at a determined position (its locus).
Macroorchidism - Abnormal development of the genitalia, showing a larger testicular volume.
Marker, Genetic marker - A known location of the genome (gene, polymorphism, DNA sequence - these concepts are overlapping since a gene or a polymorphism may be represented by a sequence ; see also Microsatellite, RFLP). A gene or a fragment of DNA sequence having a known location on a chromosome. They are used to trace or identify specific region of a gene - especially one that is associated with an inherited disease - on a chromosome. They are also used to determine a linkage group or a recombination event.
Metabotropic Glutamate Receptor - Metabotrophic glutamate receptor 5 (mGluR5) is a protein involved in normal brain function and neurotransmission. The mGluR theory : glutamate is a chemical messenger that activates signals in the brain, the most important excitatory neurotransmitter throughout the central nervous system. The metabotropic glutamate receptors (mGluRs) bind glutamate within a large extracellular domain and transmit signals through the receptor protein to intracellular signaling partners. Since mGluRs are involved in a variety of functions, abnormalities in their expression can contribute to disease. Their action is balanced by the inhibitory effects of GABA. Most mGluR5 proteins sit on the outside of the signal-receiving ends of neurons, making them easy targets for small-molecule compounds that inhibit their activity. A 2007 study showed that cutting the number of mGLuR5 receptors in half in mice that model fragile X syndrome resolves many of the symptoms of the disorder.
Methylation - See DNA methylation
mGluR5 Antagonist - Some researchers suggest that if the activation of mGluR5 goes unchecked we see the clinical symptoms of Fragile X. mGluR5 antagonists are a major part of pharmaceutical research to help restore normal brain function and alleviate symptoms.
Microsatellite - Numerous short segments of DNA that are distributed throughout the genome consisting of repeated sequences of usually two to five nucleotides. They are often used in genetics as a marker in identifying important genetic traits.
Mitral valve prolapse - Drooping down or abnormal bulging of the mitral valve's cusps backward into the atrium during the contraction of the heart.
Molecular Hybridization - in molecular biology, formation of a partially or wholly complementary nucleic acid duplex by association of single strands, usually between DNA and RNA strands or previously unassociated DNA strands, but also between RNA strands, used to detect and isolate specific sequences.
Monosomy - One chromosome is missing in the pair inherited from both parents. All cases of autosomal monosomy are lethal and the individual will not survive development.
Montessori education - Is an educational approach developed by Italian physician and educator Maria Montessori and characterized by an emphasis on independence, freedom within limits, and respect for a child’s natural psychological, physical, and social development. The child freely use cubes, cylinders with various diameters, and nestable objects, letters cut out of various materials …
Mosaic / Mosaicism - A mosaic or mosaicism denotes the presence of two or more populations of cells with different genotypes in one individual who has developed from a single fertilized egg. An individual can have both healthy cells and cells with a genetic abnormality.
mRNA (messenger RNA) - A form of RNA, transcribed from a single strand of DNA, that carries genetic information that specifies the amino acid sequence for protein synthesis.
mRNA Toxicity - The elevated mRNA levels lead to dysregulation of several proteins and subsequent neuronal and astrocyte toxicity and eventually cell death. The mRNA toxicity can involve many areas in the central nervous system in addition to the testicles, thyroid and adrenal gland.
Mutation (en) - Change in genetic information through DNA modification. The mutations affect large strands of chromosomes, small deletions of DNA or DNA insertions or simple bases (point mutation). A medical condition can result from a mutation altering the expression of one or several gene(s).
Mutation, Missense mutation - A missense mutation is a point mutation in which a single nucleotide is changed, resulting in a codon that codes for a different amino acid in the corresponding protein.
Mutation, Nonsense mutation - Biosynthesis of a protein is terminated as soon as stop codons appear. A nonsense mutation is a point mutation in a sequence of DNA that results in a premature stop codon (or nonsense codon) in the transcribed mRNA, and in a truncated, incomplete, and usually non-functional protein product.
Mutation, Point mutation - A point mutation, or single base substitution, is a type of mutation that causes the replacement of a single base nucleotide with another nucleotide of the genetic material, DNA or RNA. Often the term point mutation also includes insertions or deletions of a single base pair or several pairs.
Mutation, Splice site mutation - A splice site mutation is a genetic mutation that inserts or deletes a number of nucleotides in a specific site.
Mutation/ De novo deletion - Mutation/ Deletion that has not been inherited from a parent but that appears ex nihilo in an individual.
Neurone (en) - A neuron (nerve cell) possesses a cell body, dendrites, and an axon which is a special cellular extension that arises from the cell body and travels for a distance, as far as 1 metre in humans. Axons make contact with other cells—usually other neurons but sometimes muscle or gland cells—at junctions called synapses : dendrites usually receive signals while axons usually transmit them. Neurons connect to each other to form neural networks. Neurons are the core components of the nervous system.
Neurotransmitter (en) - Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Examples of neurotransmitters: acetylcholine, adrenaline, noradrenaline, dopamine, serotonin, histamine, glutamate, neuroactive peptides…
Nucleotide - The basic structural: unit of DNA and RNA made up of sugar, a phosphate group and a nitrogenous base (adenine, cytosine, guanine and thymine or uracil).
Nystagmus (en) - Nystagmus is a condition of involuntary movement with a weak oscillation and rotation of the eye.
Obsessive-compulsive disorder (OCD) - Sometimes FRAX children develop obsessive-compulsive disorders characterized by repetitive behaviours or rituals aimed at reducing the anxiety associated to some obsession.
Oral-facial-lingual Praxis - The oral-facial-lingual praxis consists in coordinated movements aiming at work on different soft tissues and musculature involved in swallowing, speech, mastication, facial expression, etc... The tongue, lips and cheeks are exercised.
Palilalia - A disorder of speech characterized by compulsive repetitions of utterances.
Pectus excavatum (en) - Pectus excavatum (a Latin term meaning hollowed chest) is the most common congenital deformity of the anterior wall of the chest, in which several ribs and the sternum grow abnormally. This produces a caved-in or sunken appearance of the chest. It can either be present at birth or not develop until puberty.
Penetrance - The frequency of expression of an allele when it is present in the genotype of the organism (if 9/10 of individuals carrying an allele express the trait, the trait is said to be 90% penetrant). Not all phenotypes that are expressed are manifested to the same degree.
Peripheral Neuropathy - Peripheral neuropathy - due to nerve damage - often causes weakness, numbness and pain, usually in hands and feet, but it may also occur in other body areas. Some people may experience temporary numbness, tingling, and pricking sensations (paresthesia), sensitivity to touch, or muscle weakness. Others may suffer more extreme symptoms, including burning pain (especially at night), muscle wasting, paralysis, or organ or gland dysfunction. People may become unable to digest food easily, maintain safe levels of blood pressure, sweat normally, or experience normal sexual function. A number of medications are used to reduce the painful symptoms of peripheral neuropathy.
Perseveration (en) - Children with intellectual disabilities, particularly those on the autism spectrum, perseverate. Perseverating means they do certain actions over and over again, such as repeating a phrase, shutting a door, twiddling fingers or objects, lining up toys or spinning objects. It is simply the repetition of a behaviour which seems meaningless to the observer as there is no obvious stimulus.
Pervasive developmental disorder (PDD) - Are characterized by delays in the development of multiple basic functions including socialization and communication. as opposed to specific developmental disorders (SDD). The onset of pervasive developmental disorders occurs during infancy, but the condition is usually not identified until the child is around 3 years old when developmental milestones are not met, including age appropriate motor movement and speech production.
Phenotype - The clinical outcome of an expressed gene or genes, which also refers to the outcome of the interaction of genes with environment.
Polygenic inheritance - Traits which are influenced by multiple genes or their alleles/mutations.
Polymerase (en) - An enzyme whose function is the synthesis of polymers of nucleic acids. DNA polymerase and RNA polymerase are used to assemble DNA and RNA molecules.
Polymerase Chain Reaction (PCR) - A technique that enables multiple copies of a DNA molecule to be generated by enzymatic amplification of a target DNA sequence. The polymerase chain reaction (PCR) is used to amplify a specific region of a DNA strand. A region of the genome is characterized by two short oligo-nucleotides with specific sequence that can hybridize themselves with opposite sequences thanks to the recognition of their bases after DNA has been denatured - separated into two strands through heating. A heat stable polymerase may extend the oligonucleotides (primer) of the complementary DNA strands and therefore double the sequences defined by the primers. As PCR progresses, the DNA generated is itself used as a template for replication, setting in motion a chain reaction in which the DNA template is exponentially amplified. It only require a few nanograms of genomic DNA to get in a few hours several micrograms of each isolated and desired gene or gene fragment. PCR is most used for analysis of genes and their mutations.
Polymorphism - Two or more variations in DNA sequences in a population (see 'allele').
Premutation - For diseases linked to a triplet repeat a particular length of the triplet repeat causes the disease. This limit is set at 200 CGG triplet repeats for Fragile X syndrome. Premutations with about 50 to 200 repeats of the CGG segment may mutate quicker into a full mutation with over 200 repeats of the CGG segment.
Prenatal Diagnosis or pre-implantation genetic Diagnosis - Pre-implantation genetic diagnosis (PGD or PIGD) refers to genetic profiling of embryos prior to implantation, PGD is considered in a similar fashion to prenatal diagnosis. When used to screen for a specific genetic disease, its main advantage is that it avoids selective pregnancy termination as the method makes it highly likely that the baby will be free of the disease under consideration.
Primer - A primer is a strand of nucleic acid that serves as a starting point for DNA synthesis. A marked primer highlights the start of a DNA sequence or serves as start of the cDNA synthesis. Two primers that point at each other identify the sequence to be amplified by PCR (see item).
Promoter - A promoter is a gene segment that cannot be translated into protein (amino acid). The promoter is a DNA sequence located upstream in the gene and they determine the occurrence of translations in mRNA (see 'transcription').
Protein (en) - Protein molecule composed with amino acids. Most vital functions of the body are executed by various proteins. Protein function and form are specified by a chain of 20 various protein compounds, the amino acids. This chain is determined by the chain of the various bases in the gene. One gene contains the information to create one protein.
Receptor - A protein molecule embedded in the membrane of a cell, that can identify specific kinds of signalling molecules (hormone, growth factor).
Restriction fragment length polymorphism, or RFLP (commonly pronounced “rif-lip”) - A technique that exploits variations in homologous DNA sequences. It refers to a difference between samples of homologous DNA molecules that come from differing locations of restriction enzyme sites. In RFLP analysis, the DNA sample is broken into pieces (digested) by restriction enzymes and the resulting restriction fragments are separated according to their lengths.
Retrovirus - Virus whose genome is constituted with RNA. Its specificity is to possess one enzyme that enables transcription from its viral RNA genome into DNA molecule in the host cells (see 'vector').
RNA - One-strand copy of DNA or of DNA segments.
Screening (en) - The identification of persons from a population with a particular disorder or those who might carry a gene for such a disorder.
Seizures - Seizure is defined by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Epileptic seizures can occur in someone who does not have epilepsy – as a consequence of head injury, drugs, toxins, eclampsia or febrile convulsions, for example.
Sensory integration - see 'Therapy': Sensory integration therapy
Sequencing - DNA sequencing is the process of determining the nucleotide order in a polymer molecule e.g. DNA, RNA or protein. Most often DNA sequencing is obtained by stopping the synthesis of a DNA strand initiated with a short fragment (see "primer"). A nucleotide slightly different because it is missing a specific base is introduced to stop the synthesis. The process results in a series of related DNA fragments that are terminated only at positions where that particular nucleotide is used. The fragments may then be size-separated. The analysis of the different size fragments enables the ventilation of the original DNA sequence.
Sex Chromosomes - The X and Y chromosomes responsible for sex type (XX in women and XY in men).
Skin picking (Dermatillomania) - Skin picking is an impulse control disorder characterized by the repeated urge to pick at one's own skin, often to the extent that damage is caused.
Snoezelen (en) - Snoezelen (pronounced /ˈsnuzələ(n)/) or controlled multisensory environment (MSE) is a therapy for people with autism or developmental disabilities. It consists of placing the person in a soothing and stimulating environment, the 'Snoezelen room'.
Southern Blot (en) - A diagnosis technique for detecting DNA fragments by hybridization. After its inventor Ed Southern. DNA fragments are fixed on a gel (blot) and may be identified by hybridization with a single-stranded nucleic acid fragment (DNA or RNA) whose one of the bases has been tagged with radioactive or fluorescent markers (the probe).
Special education / A special educational needs (SEN) teacher (UK) - Special education is educating in a way that addresses the students' individual differences and needs. Ideally, this process involves the individually planned and systematically monitored arrangement of teaching procedures, adapted equipment and materials, accessible settings, and other interventions designed to help learners with special needs achieve a higher level of personal self-sufficiency and success in school and community.
Specific developmental disorders (SDD) - Specific developmental disorders are disorders in which development is delayed in one specific area or areas, and in which basically all other areas of development are not affected. Opposed to pervasive developmental disorders.
Staring spells - Staring episodes
Synapse (en) - At a synapse, the plasma membrane of the signal-passing neuron comes into close apposition with the membrane of the target cell and neurotransmitters are released.
Syndrome (en) - A combination of clinical features' or a group of symptoms' forming a recognisable entity such as a specific disorder, condition or a disease.
Tactile defensiveness - Common symptoms of sensory defensiveness include intolerance of high-pitched noises, intolerance of chewing sounds, intolerance of overhead lights (especially fluorescent lighting); experiencing a feeling of being attacked upon being touched (especially from light touch or sudden touch); intolerance of certain types of fabrics in contact with the skin; becoming nauseated upon smelling something that does not smell bad to neurotypical individuals; difficulty maintaining eye-contact; severe intolerance of foods due to taste, texture, or temperature; and generally becoming overwhelmed when exposed to a lot of sensory stimuli at once.
Tantrum - Emotional outbreak, manifestation of a loss of control and frustration
Therapy, therapists: Kinesiology, human kinetics - Kinesiology addresses physiological, mechanical, and psychological mechanisms. Applications of kinesiology to human health include: biomechanics and orthopedics; strength and conditioning; sport psychology; methods of rehabilitation, such as physical and occupational therapy; and sport and exercise.
Therapy, therapists: Neurology - Neurology is the branch of medicine concerned with the study and treatment of disorders of the nervous system.
Therapy, therapists: Neuropsychology - Neuropsychology is a specific branch of clinical psychology that involves using various tests to better explain the relationship between brain functioning and behaviour. Clinical neuropsychologists diagnose, assess and treat patients with cognitive deficits, brain injuries and progressive neurocognitive disorders.
Therapy, therapists: Occupational therapy (OT) - Provides practical support to people with physical and mental illness, disability, long term conditions, or those experiencing the effects of ageing, to do the things they need or want to do. It enables people of all ages to carry out practical and purposeful activities (often referred to as ‘occupation’). Occupational therapy considers all our needs e.g. physical, psychological, social and environmental – and helps to increase people’s independence and satisfaction in all aspects of life.
Therapy, therapists: Osteopathy - Osteopathy is a system of medicine that emphasizes the theory that the body can make its own remedies, given normal structural relationships, environmental conditions, and nutrition. It differs from allopathy primarily in its greater attention to body mechanics and manipulative methods in diagnosis and therapy.
Therapy, therapists: Osteopathy - Osteopathy is a system of medicine that emphasizes the theory that the body can make its own remedies, given normal structural relationships, environmental conditions, and nutrition. It differs from allopathy primarily in its greater attention to body mechanics and manipulative methods in diagnosis and therapy.
Therapy, therapists: Pediatric Psychiatry (US) / Child Psychiatry (UK) - Child/pediatric psychiatrists diagnose, evaluate and treat emotional, mental or behavioural disorders that affect adolescents, children and their families. They diagnose the nature and extend of disorders, determine the best course of action and treatment and they talk about this plan with the child and his parents. Child psychiatrists work in multiple settings like schools, private and public clinics and hospitals.
Therapy, therapists: Physiotherapy (UK), Physical therapy (US) - Physical therapists generally focus on gross motor functioning, postural control, sitting, standing, and walking. Physical therapy is primarily concerned with the remediation of impairments and disabilities and the promotion of mobility, functional ability, quality of life and movement potential through examination, diagnosis and physical intervention. Physical therapy involves the interaction between therapist, patients, their families and other health care professionals, in a process where movement potential is assessed and diagnosed and goals are agreed upon. Physical therapists and occupational therapists often work together in conjunction to provide treatment for patients.
Therapy, therapists: Psychology / Educational Psychologists / School Psychologist - School Psychologists, Educational Psychologists are part of the multidisciplinary team and often administer the individual IQ test and other measures. They also consult regarding placement, academic interventions, social emotional skill development, and learning profiles. They may also provide psychological counselling for children and parents.
Therapy, therapists: sensory integration therapy - Sensory integration therapy is a theory and treatment approach used by therapists to provide an understanding of the relationship between sensory processing and consequent behaviour and performance.
Therapy, therapists: Speech and language therapy (UK, Eire), Speech-Language Therapy (US, CA) - is concerned with the management of disorders of speech, language, communication and swallowing in children and adults. Speech Pathologists assess receptive and expressive speech and language, refer for medical assessment when necessary, and provide therapeutic services.
Therapy, therapists: Therapeutic Horseback Riding / Hippotherapy - Hippotherapy is a form of physical, occupational and speech therapy in which a therapist uses the characteristic movements of a horse to provide carefully graded motor and sensory input. Unlike therapeutic horseback riding (where specific riding skills are taught), the movement of the horse is a means to a treatment goal when utilizing hippotherapy as a treatment strategy.
Transcription (en) - The genetic information is transferred (transcribed) from DNA to RNA inside the cell nucleus.
Translation (en) - The process of protein synthesis from messenger RNA where the messenger RNA directs the assembly of amino acids that makes the protein.
Tremor (en) - Any abnormal repetitive shaking movement of the body, most often occurring in the hands. An intentional tremor occurs when grasping as opposed to a tremor at rest.
Trinucleotide repeat disorders - A set of genetic disorders caused by trinucleotide repeat expansion, a kind of mutation where trinucleotide repeats in certain genes exceeding the normal, stable threshold, which differs per gene. The mutation is a subset of unstable microsatellite repeats that occur throughout all genomic sequences. If the repeat is present in a healthy gene, a dynamic mutation may increase the repeat count and result in a defective gene.
Trisomy - A trisomy is the most frequent type of abnormal number of chromosomes due the presence of an extra chromosome on one of the pairs 13, 18, 21 and X.
Trophoblast (en) - The outer layer of cells of the embryo of placental mammals, which is attached to the uterus wall and absorbs nourishment from the uterine fluids.
Vector - A vector is a DNA molecule used as a vehicle to transfer and multiply foreign genetic material in various sizes (most often restriction fragments) into another cell. The major types of vectors are plasmids (100-20 000, bacteria), phages ((100-35 000, bacteria), cosmids (10 000-45 000,bacteria), and YAC (see 'YAC' ; 10 000-10 000 000, yeasts). In genetic therapy: particles that can transfer DNA fragments in target cells : DNA viruses (e.g. adenovirus), retroviruses (see 'retrovirus'), lipid/DNA complexes (liposomes).
X-inactivation - A process in female mammals in which one of the two X chromosomes is 'turned off'.
YAC (en) - Yeast Artificial Chromosome (see 'vector').
Zygote (en) - The cell resulting from the union of sperm and egg cell and enabling the development of the organism. This cell contains in principle all genetic information of the cells of the future organism.