Glossary
Allele: one of a number of alternative forms of the same gene or same genetic locus. It is the alternative form of a gene for a character producing different effects. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation. However, many variations at the genetic level result in little or no observable variation. Most multicellular organisms have two sets of chromosomes, that is, they are diploid. These chromosomes are referred to as homologous chromosomes. Diploid organisms have one copy of each gene (and therefore one allele) on each chromosome. If both alleles are the same, they are homozygotes. If the alleles are different, they are heterozygotes.
Antisense oligonucleotides: Antisense oligonucleotides are synthesized in the hope that they can be used as therapeutic agents — blocking disease processes by altering the synthesis of a particular protein. This would be achieved by the binding of the antisense oligonucleotide to the mRNA from which that protein is normally synthesized
Antisense therapy: Antisense therapy is a form of treatment for genetic disorders or infections. When the genetic sequence of a particular gene is known to be causative of a particular disease, it is possible to synthesize a strand of nucleic acid (DNA, RNA or a chemical analogue) that will bind to the messenger RNA (mRNA) produced by that gene and inactivate it, effectively turning that gene “off”.
Apoptosis: Apoptosis or programmed cell death, is a naturally occurring process in the body. It involves a controlled sequence of steps in which cells signal self termination. Apoptosis works to keep the body’s natural process of cell division or mitosis in check.
Autonomic nervous system: A part of the vertebrate nervous system that innervates smooth and cardiac muscle and glandular tissues and governs involuntary actions (as secretion, vasoconstriction, or peristalsis) and that consists of the sympathetic nervous system and the parasympathetic nervous system—called also vegetative nervous system.
Autophagy: The word autophagy is derived from Greek words “auto” meaning self and “phagy” meaning eating. Autophagy is a normal physiological process in the body that deals with destruction of cells in the body.
Autosome: Any of the non-sex-determining chromosomes. Human cells have 22 pairs of autosomes.
Autosomal Recessive Inheritance: Pattern of inheritance in which disease results only when an individual inherits two gene mutations for a particular disease. If both members of a couple are carriers of the same disease gene, there is a one in four or 25% chance in each pregnancy for a child to be affected.
Carrier: An individual who has one copy of an altered gene and one working copy of the same gene. Carriers are healthy individuals. Usually, the only consequence of being a carrier of a recessive genetic trait is the possibility of transmitting the particular genetic trait to a child.
Cell: A small, watery, membrane-bound compartment filled with chemicals; the basic subunit of any living thing.
Chromosome: A structure found in the nucleus of a cell that contains genetic information. Human cells contain 46 chromosomes, which are in pairs. Each chromosome contains thousands of individual genes, which determine an individual’s characteristics.
Compound heterozygote: The presence of two different mutant alleles at a particular gene locus, one on each chromosome of a pair.
The human genome contains two copies of each gene, a paternal and a maternal allele. A mutation affecting only one allele is called heterozygous. A homozygous mutation is the presence of the identical mutation on both alleles of a specific gene. However, when both alleles of a gene harbor mutations, but the mutations are different, these mutations are called compound heterozygous. (also called a genetic compound).
Consanguinity: (“blood relation”, from the Latin consanguinitas) is the property of being from the same kinship as another person. In that respect, consanguinity is the quality of being descended from the same ancestor as another person.
Dementia: A usually progressive condition (as in Alzheimer’s disease) marked by the development of multiple cognitive deficits (as memory impairment, aphasia, and inability to plan and initiate complex behavior).
DNA (deoxyribonucleic acid): The molecule that encodes the genes responsible for the structure and function of living organisms and allows the transmission of genetic information from generation to generation.
Enzyme: A protein that acts as a catalyst to cause chemical changes in other substances. Enzymes are often required for the normal metabolism, or breakdown, of substances in the body.
Eu·kar·y·ote also eu·car·y·ote
Gene: The fundamental unit of heredity. A gene is composed of a sequence of DNA required to produce a functional protein. The information in the genes is passed from parent to child.
Gene knockdown: Gene knockdown refers to an experimental technique by which the expression of one or more of an organism’s genes is reduced. The reduction can occur either through genetic modification or by treatment with a reagent such as a short DNA or RNA oligonucleotide that has a sequence complementary to either gene or an mRNA transcript.
Genetic Counseling: The communication process that helps individuals, couples or families to understand genetic information such as occurrence, or the risk of occurrence, of a genetic disorder in a family. Genetic counselors help individuals make informed decisions about family planning.
Genotype/Phenotype: genotype is the set of genes responsible for a particular trait; phenotype is the physical expression of that trait
Glycogen Storage Disease: any of several metabolic disorders (as McArdle’s disease or Pompe’s disease) that are characterized especially by abnormal deposits of glycogen in tissue, are caused by enzyme deficiencies in glycogen metabolism, and are usually inherited as an autosomal recessive trait.
Glycogen Storage Disease Type IV: It is a condition caused by genetic mutations in the Glycogen Branching Enzyme that lead to little or no functional enzyme. The disease has many subtypes, but the most frequently seen type is characterized by liver disease within the first few months of life, which eventually leads to liver failure. The signs and symptoms of other forms may include stiff joints throughout the body (arthrogryposis), underdeveloped lungs, low muscle tone (hypotonia), weakened heart muscle (cardiomyopathy), enlarged liver (hepatomegaly), enlarged spleen (splenomegaly), and muscle wasting (atrophy).
Glycogen Synthase: The protein encoded by this gene catalyzes the addition of glucose monomers to the growing glycogen molecule through the formation of alpha-1,4-glycoside linkages. Mutations in this gene are associated with muscle glycogen storage disease. Defects in GYS1 are the cause of muscle glycogen storage disease type 0 (GSD0b); Metabolic disorder characterized by fasting hypoglycemia presenting in infancy or early childhood. The role of muscle glycogen is to provide critical energy during bursts of activity and sustained muscle work.
Haplotype: A haplotype is a group of genes within an organism that was inherited together from a single parent.
Heterozygote: Having two alleles that are different for a given gene.
High-throughput screening (HTS): this screening process allows a researcher to quickly conduct millions of chemical, genetic or pharmacological tests. Through this process one can rapidly identify active compounds, antibodies or genes which modulate a particular biomolecular pathway. The results of these experiments provide starting points for drug design and for understanding the interaction or role of a particular biochemical process in biology. tehy are testing 10,000 compounds and then will share his date with other centers that are testing an additional 20,000 compounds.
Homozygote: Having identical alleles at one or more loci in homologous chromosome segments.
Ischemia: A deficient supply of blood to a body part (as the heart or brain) that is due to obstruction of the inflow of arterial blood (as by the narrowing of arteries by spasm or disease).
Leukodystrophy: Any of several inherited diseases characterized by progressive degeneration of myelin in the brain, spinal cord, and peripheral nerves.
Molecule: A group of atoms arranged to interact in a particular way; one molecule of any substance is the smallest physical unit of that particular substance.
Mouse Model: Among the many advantages to using the mouse as a model organism, the most important is their striking similarity to humans in anatomy, physiology, and genetics. Over 95% of the mouse genome is similar to our own, making mouse genetic research particularly applicable to human disease.
Mutation: A gene mutation is a permanent change in the DNA sequence that makes up a gene. Mutations range in size from a single DNA building block (DNA base) to a large segment of a chromosome.
Neurogenic Bladder: A condition that causes affected individuals to have progressive difficulty controlling the flow of urine due to damage to the nerves that control bladder functions.
Nonsense mutation: A nonsense mutation is a genetic mutation in a DNA sequence that results in a shorter, unfinished protein product.
Peripheral Neuropathy: A problem with the functioning of the nerves outside the spinal cord. Symptoms of peripheral neuropathy may include numbness, weakness, burning pain (especially at night), and loss of reflexes.
Point Mutation: A gene mutation involving the substitution, addition, or deletion of a single nucleotide base.
Polyglucosans: An abnormal form of glycogen that cannot be broken down and used for fuel. Instead, they build up to form clumps that can damage cells, particularly neurons.
Promoter: In genetics, a promoter is a region of DNA that initiates transcription of a particular gene.
Spasticity: A spastic state or condition ; especially : muscular hypertonicity with increased tendon reflexes.
Triple-helix-forming oligonucleotide gene therapy: Triple-helix-forming oligonucleotide gene therapy targets the DNA sequence of a mutated gene to prevent its transcription. This technique delivers short, single-stranded pieces of DNA, called oligonucleotides that bind specifically in the groove between a gene’s two DNA strands. This binding makes a triple-helix structure that blocks the DNA from being transcribed into mRNA.
Urosepsis: A toxic condition caused by the extravasation of urine into bodily tissues.
White Matter: Neural tissue especially of the brain and spinal cord that consists largely of myelinated nerve fibers bundled into tracts, has a whitish color, and typically underlies the gray matter.
Wild type: The typical form of an organism, strain, gene, or characteristic as it occurs in nature, as distinguished from mutant forms that may result from selective breeding.