Dictionary

human gene therapy See gene therapy.

human genome See genome, human.

Human Genome Organization See HUGO.

Human Genome Project Begun formally in 1990, the US Human Genome Project was an international effort coordinated by the US. Its goals included the identification and sequencing (ordering) of all the bases in the human genome. US participation in this monumental undertaking was supported by funds from the National Institutes of Health (NIH) and the…

homocysteine An amino acid that is produced by the human body, usually as a byproduct of consuming meat. Homocysteine is normally converted into other amino acids. An abnormal accumulation of homocysteine, which can be measured in the blood, can be a marker for the development of heart disease. Elevated levels of homocysteine in the blood…

homocystinuria A genetic disease that is due to an enzyme deficiency that permits a buildup of the amino acid homocysteine. Progressive mental retardation is common, but does not always occur, in untreated cases of homocystinuria. The finding of vascular disease and premature arteriosclerosis in persons with homocystinuria led to the theory that homocysteine may be…

homolog 1 One chromosome of a pair. 2 A gene from one species that has a common origin and functions the same as a gene from another species. Also spelled homologue.

homologous 1 Similar in appearance, form, or function. 2 Paired or matched; usually referring to the relationship between two chromosomes that are paired and so are homologs of each other.

homologous chromosomes A pair of chromosomes that contain the same gene sequences, each derived from one parent.

homology Similarity in DNA or protein sequences between individuals or between species.

homosexual 1 A person who is sexually attracted to persons of the same sex. Colloquially known as gay. 2 The act or habit of same-sex attraction.

homosexuality Sexuality directed toward someone of the same sex.