Dictionary

chromosome complement The whole set of chromosomes for a species. In humans, the normal chromosome complement consists of 46 chromosomes, including the 2 sex chromosomes. Also known as the karyotype.

chromosome disorder An abnormal condition due to something unusual in an individual’s chromosomes. For example, Down syndrome is a chromosome disorder caused by the presence of an extra copy of chromosome 21, and Turner syndrome is most often due to the presence of only a single sex chromosome: one X chromosome.

chromosome inversion A condition in which a chromosome segment is clipped out, turned upside down, and reinserted back into the chromosome. A chromosome inversion can be inherited from one or both parents, or it may be a mutation that appears in a child whose family has no history of chromosome inversion. An inversion can be…

chromosome inversion, paracentric A type of chromosome rearrangement in which a chromosomal segment that does not include the centromere (and is therefore paracentric) is snipped out of a chromosome, inverted, and inserted back into the chromosome. The feature that makes it paracentric is that both breaks are on the same side of the centromere, so…

chromosome inversion, pericentric A basic type of chromosome rearrangement in which a segment that includes the centromere (and is therefore pericentric) is snipped out of a chromosome, inverted, and inserted back into the chromosome. The feature that makes it pericentric is that the breaks are on both sides of the centromere.

chromosome map The chart of the linear array of genes on a chromosome. The Human Genome Project contributes to the mapping of the human chromosomes. See also Human Genome Project.

chromosomes in multiple miscarriages Chromosome abnormalities (such as deletions, additions, or translocations) that are responsible for causing miscarriages. A couple that has had more than one miscarriage has about a 5 percent chance that one member of the couple is carrying an irregular chromosome that is responsible for the miscarriages.

chronic In medicine, lasting a long time. A chronic condition is one that lasts 3 months or more. Chronic diseases are in contrast to those that are acute (abrupt, sharp, and brief) or subacute (within the interval between acute and chronic).

chronic arthritis, systemic-onset juvenile See Still’s disease.

chronic bronchitis See bronchitis, chronic.

chondroplasia The formation of cartilage by specialized cells called chondrocytes.

chondrosarcoma A malignant tumor that arises in cartilage cells (chondroblasts). Chondrosarcoma can be primary or secondary. Primary chondrosarcoma forms in bone and is a disease in children. Secondary chondrosarcoma arises from a preexisting benign defect of cartilage (such as an osteochondroma or enchondroma), usually after age 40. The main treatment is surgery. See also cartilage;…