Term
|
Definition
| Different forms of a gene or DNA occupying the same place on a pair of chromosomes; an allele for each gene is inherited from each parent. |
|
|
Term
|
Definition
| The tendency for certain genetic disorders to display earlier onset and increased severity in successive generations of a family. |
|
|
Term
|
Definition
| A group of abnormalities of unknown cause that occur together more often than is expected by chance. |
|
|
Term
|
Definition
| A single chromosome from any one of the 22 pairs of chromosomes not involved in sex determination (X or Y); humans have 22 pairs of autosomes. |
|
|
Term
|
Definition
| Any individual who carries a single copy of an altered gene or mutation for a recessive condition on one chromosome of a chromosome pair and an unaltered form of that gene on the other chromosome; a carrier generally is not affected by the gene alteration; on the average, each person in the general population is a carrier of five or six gene mutations for recessive disorders. |
|
|
Term
|
Definition
| The basic unit of life, and the working unit of all living systems. |
|
|
Term
|
Definition
| Related by having a common ancestor; close blood relationship. |
|
|
Term
|
Definition
| A process that occurs during meiosis in which homologous maternal and paternal chromosomes break and exchange corresponding sections of DNA and then rejoin; this process can cause an exchange of alleles between chromosomes and provides human diversity. |
|
|
Term
|
Definition
| The study of chromosomes and alterations to health caused by abnormalities in the number or structure of chromosomes. |
|
|
Term
|
Definition
| A characteristic or gene that is apparent even when the relevant gene is present in only one copy; a person with a dominant gene usually expresses that gene trait. |
|
|
Term
|
Definition
| The study of human congenital defects or abnormalities of body structure that begin before birth. |
|
|
Term
|
Definition
| Describes any factor that can affect gene function (usually by changing gene expression, or translation) without changing the DNA sequence. |
|
|
Term
|
Definition
| A reproductive cell (i.e., an ovum or sperm) each containing a single copy of each of the 23 chromosomes that make up the human genome. |
|
|
Term
|
Definition
| A sequence of DNA on a chromosome that represents a fundamental unit of heredity; occupies a specific spot on a chromosome (gene locus). |
|
|
Term
|
Definition
| When the protein product of a gene is visible (presence of a body structure or identifiable through biochemical tests such as insulin or phenylalanine levels). |
|
|
Term
|
Definition
| Any disease associated with gene dysfunction. While genetics diseases have traditionally been thought of as relatively rare inherited diseases, it is now known that nearly all diseases have a genetic component. |
|
|
Term
|
Definition
| The entire DNA sequence that makes up the complete genetic information of a gamete, an individual, a population, or a species. |
|
|
Term
|
Definition
| The study of all the genes in the human genome together, including their interactions with each other, the environment, and the influence of other psychosocial and cultural factors. |
|
|
Term
|
Definition
| The genes and the variations therein that a person inherits from his or her parents. |
|
|
Term
|
Definition
| Nonidentical copies of a particular gene (different alleles) on the paired chromosomes. |
|
|
Term
|
Definition
| Chromosomes that are members of the same pair and normally have the same number and arrangement of genes; usually one copy is from the mother and the other copy is from the father. |
|
|
Term
|
Definition
| Identical copies of a particular gene (same alleles) on both paired chromosomes. |
|
|
Term
|
Definition
| The total amount of the DNA (genes) in an individual's cells. |
|
|
Term
|
Definition
| The random distribution of different combinations of parental genes to gametes. |
|
|
Term
|
Definition
| A chromosomal alteration in which a gene or DNA sequence in a segment of a chromosome has been reversed. |
|
|
Term
|
Definition
| The arrangement of chromosome pairs by number according to length, centromere position, and banding patterns. |
|
|
Term
|
Definition
| a serious structural defect present at birth that may have severe medical or cosmetic consequences interfere with normal functioning of body systems, lead to a lifelong disability, or even cause early death. |
|
|
Term
|
Definition
| Cell division that produces reproductive cells (egg or sperm); meiosis results in daughter cells, which contain half of the chromosome complement (23). |
|
|
Term
|
Definition
| A laboratory method in which labeled RNA from a specimen is added to a glass slide or other platform upon which DNA fragments are arranged. Useful for identifying and quantifying mRNA and indicating which genes are actively expressed in a tissue. |
|
|
Term
|
Definition
| An unusual morphologic feature that is of no serious medical or cosmetic concern. |
|
|
Term
|
Definition
| Cell division that results in new (daughter) cells that are genetically identical to each other and to the parent cell. |
|
|
Term
|
Definition
| When one member of the chromosome pair is missing, for example, Turner syndrome (45, XO). |
|
|
Term
|
Definition
| A chromosome variation or abnormality that occurs after fertilization during mitosis at an early cell stage so not all cells are affected with the variation; for example, a child who is mosaic for Down syndrome will have some cells with two copies of chromosome 21 and some that have an extra chromosome 21. |
|
|
Term
|
Definition
| Health conditions determined by multiple factors, including genetic and environmental factors, each having an additive effect. |
|
|
Term
|
Definition
| An error in cell division where a pair of homologous chromosomes do not separate as expected, resulting in monosomy or trisomy in gametes. |
|
|
Term
|
Definition
| A small cellular structure such as a ribosome or mitochondria that performs specific cellular functions. |
|
|
Term
|
Definition
| A pictorial family history diagram that traces genetic characteristics and disorders in a family. |
|
|
Term
|
Definition
| The percentage or likelihood that an individual who has inherited a gene mutation will actually express the disease signs and symptoms in his or her lifetime. |
|
|
Term
|
Definition
| The study of how an individual's genotype affects his or her response to medications. |
|
|
Term
|
Definition
| The expression of a person's entire physical, biochemical, and physiologic makeup, as determined by the individual's genotype and environmental factors. |
|
|
Term
|
Definition
| DNA sequences that occur in more than one form but provide the genetic "directions" for the same thing. |
|
|
Term
|
Definition
| The family member around whom a family history is collected. |
|
|
Term
|
Definition
| The study of the interactions of expressed proteins in a cell. |
|
|
Term
|
Definition
| A characteristic that is apparent only when two copies of the gene encoding it are present, one from the mother and one from the father. |
|
|
Term
|
Definition
| One of the chromosomes (X or Y) involved in sex determination. Normal human females have two X chromosomes in each cell, while normal males have one X and one Y. |
|
|
Term
| single nucleotide polymorphism |
|
Definition
| A variation in DNA sequence in which a single nucleotide base (A, T, C, or G) is substituted for another. |
|
|
Term
|
Definition
| A collection of anomalies that occur in a consistent pattern and have a common cause. |
|
|
Term
|
Definition
| The joining of a part of or a whole chromosome to another separate chromosome. |
|
|
Term
|
Definition
| Having three chromosomes instead of the usual two as in trisomy 21 or Down syndrome. |
|
|
Term
|
Definition
| The most common type of gene; designated as normal. |
|
|
Term
|
Definition
| Any gene found on the X chromosome, or traits determined by such genes; also refers to the specific mode of inheritance of such genes; one altered gene on an X chromosome in a male can produce disease, such as hemophilia. |
|
|
Term
|
Definition
|
|
