Iowa Institute of Human Genetics

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  • C

    C:

    See cytosine

    Candidate gene:

    A gene suspected of being involved (responsible for) in a genetic disease due to location in a chromosomal region or gene product function.

    Carrier:

    An individual with a single copy of a genetic variant at a given locus, and the wild type copy of the gene on the other chromosome for a recessive condition (i.e. heterozygous for a disease-causing allele). These individuals usually do not have symptoms of the condition, but may pass on the genetic variant to their children. If both parents are carriers of genetic variants for the same disease-causing gene each child has a 1 in 4 (25%) chance of inheriting both genetic changes and being affected by the disease. Everyone is a carrier of several genetic variants for recessive disorders.

    Carrier Testing:

    Genetic testing performed to determine if asymptomatic individuals have a genetic variant for an autosomal recessive or X-linked recessive disorder of chromosome rearrangement. Typically performed to determine recurrence risks for a specific disease in a family or population.

    cDNA (Complementary DNA):

    DNA synthesized from a messenger RNA template which lacks introns of the gene.

    CEPH:

    Centre d'Etude du Polymorphisme Humain. An organization that collected population samples in 1980 that are commonly used in human genetics research.

    CEU:

    Utah residents with ancestry from northern and western Europe (CEU). A sample set commonly used in human genetics research to represent the people of northern and western European ancestry. The samples were collected from individuals living in Utah. No phenotypic information was collected on these samples.

    CHB:

    See Han Chinese in Beijing, China.

    chIP:

    Chromatin immunoprecipitation

    chrm/chr:

    See chromosome

    Chromosome:

    A structure found in every cell of the body that contains DNA. Humans have 46 chromosomes, 22 pairs of autosomes, and 2 sex chromosomes which we inherit from our parents.

    Chromosome disorder:

    A condition due to the gain, loss, or rearrangement of an entire or part of a chromosome.

    Clinical heterogeneity:

    Different clinical presentations within the same disorder.

    Cluster: 

    A group of linked computers, working together thus in many respects forming a single computer.

    CNV:

    See copy-number variation

    Coding region:

    All the exons of a gene which result in the protein product of the gene (also known as open reading frame).

    Common allele:

    At a given locus, the nucleotide seen most frequently in a given population.

    Complex disease:

    A disease or disorder which does not follow a mendelian inheritance pattern. Typically, complex diseases are the result of multiple susceptibility alleles along with environmental factors. Examples include, heart disease, obesity, diabetes, and cancer. (also known as multifactorial diseases)

    Compound heterozygote:

    When an individual has two different variant alleles in a given gene which results in disease.

    Concordance:

    When both members of a twin pair have a given trait. (Compare to discordant)

    Congenital:

    Present at birth.

    Consanguinity:

    Related by a common ancestor. A consanguineous marriage is a marriage between two close relatives.

    Consultand:

    Anyone who consults a healthcare provider/genetic counselor for genetic information.

    Copy-number variation (CNV):

    A segment of DNA or entire copy of a gene which varies in the number of copies present between individuals.

    Cytogenetics:

    The study of the physical appearance and function of chromosomes.