Cancer(KAN-ser) A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the…
candidate geneA gene whose deduced function (on the basis of DNA sequence) suggests that it may be involved in the genetic control of an aspect of phenotype.
Capillary arrayGel-filled silica capillaries used to separate fragments for DNA sequencing. The small diameter of the capillaries permit the application of higher…
carcinogen(kar-SIN-o-jin) Any substance that causes cancer.
carcinoma(KAR-sih-NOH-muh) Cancer that begins in the skin or in tissues that line or cover internal organs.
carrierA heterozygous individual bearing a recessive mutant allele for a defective condition that is "masked" by the presence of the dominant normal allele; the…
cDNA libraryA library composed of complementary copies of cellular mRNAs. (See Library.)
CellThe fundamental level of structural organization in complex organisms. Eukaryotic cells contain a nucleus (with chromosome s) and cytoplasm with the…
centiMorgan(Abbreviation: cM). Unit of map distance. For small recombination fractions, cM and % recombination frequency are equivalent.
Centimorgan (cM)A unit of measure of recombination frequency. One centimorgan is equal to a 1% chance that a marker at one genetic locus will be separated from a marker…
CentromereThe central portion of the chromosome to which the spindle fibers attach during mitotic and meiotic division.
Chimera (pl. chimaera)An organism that contains cells or tissues with a different genotype. These can be mutated cells of the host organism or cells from a different organism…
ChimeraplastyA method designed to create defined alterations in DNA sequence at a target locus, with potential both for gene therapy and for investigating gene…
Chloroplast chromosomeCircular DNA found in the photosynthesizing organelle (chloroplast) of plants instead of the cell nucleus where most genetic material is located.
ChromomereOne of the serially aligned beads or granules of a eukaryotic chromosome, resulting from local coiling of a continuous DNA thread.
Chromosomal inversionChromosome segments that have been turned 180 degrees. The gene sequence for the segment is reversed with respect to the rest of the chromosome.
Chromosome(KROH-muh-some) Part of a cell that contains genetic information. Except for sperm and eggs, all human cells contain 46 chromosomes.
Chromosome paintingAttachment of certain fluorescent dyes to targeted parts of the chromosome. Used as a diagnositic for particular diseases, e.g. types of leukemia.
CloningThe mitotic division of a progenitor cell to give rise to a population of identical daughter cells or clones.
Cloning vectorA small, self-replicating DNA molecule - usually a plasmid or viral DNA chromosome - into which foreign DNA is inserted in the process of cloning genes or…
CodominanceSituation in which two different alleles for a genetic trait are both expressed. See also: autosomal dominant, recessive gene
CodonA group of three nucleotides that specifies addition of one of the 20 amino acids during translation of an mRNA into a polypeptide.
Coisogenic or congenicNearly identical strains of an organism; they vary at only a single locus.
Comparative genomicsThe study of human genetics by comparisons with model organisms such as mice, the fruit fly, and the bacterium E. coli.
Complementary DNA (cDNA)DNA that is synthesized in the laboratory from a messenger RNA template.
Complementary sequenceNucleic acid base sequence that can form a double-stranded structure with another DNA fragment by following base-pairing rules (A pairs with T and C with…
Complex traitTrait that has a genetic component that does not follow strict Mendelian inheritance.
ConfidentialityIn genetics, the expectation that genetic material and the information gained from testing that material will not be available without the donor's consent.
CongenitalAny trait or condition that exists from birth. See also
Conserved sequenceAn identical or highly similar sequence of nucleotides or amino acids which occurs as part, or all of a number of different genes or protein s, in either…
contigA set of overlapping cloned DNA fragments that can be assembled to represent a defined region of the chromosome or genome from which they were obtained.
Contig mapA map depicting the relative order of a linked library of overlapping clones representing a complete chromosomal segment.
CosmidA synthetic plasmid which incorporates the cos ends, and one or more selectable markers such as an antibiotic resistance gene.
craniosynostosisA birth defect whereby an infant's skull bones are already fused at birth. Because this defect may interfere with the ability of the brain to grow…
Crossing overThe exchange of DNA sequences between chromatids of homologous chromosomes during meiosis.
cystic fibrosisA common hereditary disease in which exocrine (secretory) glands produce abnormally thick mucus.
cytogenetic mapThe visual appearance of a chromosome when stained and examined under a microscope.
Cytogenetics(SY-toh-jeh-NEH-tix) The study of chromosomes and chromosomal abnormalities.
Cytological bandAn area of the chromosome that stains differently from areas around it. See also: cytological map
Cytological mapA type of chromosome map whereby genes are located on the basis of cytological findings obtained with the aid of chromosome mutations.