Cyclopia: A congenital abnormality (birth defect) in which there is only one eye. That eye is centrally placed in the area normally occupied by the root of the nose. There is a missing nose or a nose in the form of a proboscis (a tubular appendage) located above the eye.
Cyclopia and milder forms of the same developmental disorder result from holoprosencephaly which is a failure of the embryonic forebrain to subdivide properly. (The embryonic forebrain is normally responsible for inducing the development of the orbits.) Chromosome abnormalities (such as trisomy 13) and gene mutations can disrupt this process. So also can certain toxins, some of them found in wild plants.
The term “cyclopia” comes from the Cyclops, the one-eyed giants of Greek mythology, a mythical race of lawless giant shepherds who lived in Sicily. They had a single large round eye in the center of the forehead. The word “cyclops” itself comes from the Greek “kyklos” (circle) + “ops” (eye). Cyclopia is also called synophthalmia.
Cyclops: A common freshwater crustacean. Some species of Cyclops serve as hosts for parasites such as the guinea worm, the cause of dracunculiasis (guinea worm disease). The Cyclops were one-eyed giants of Greek mythology, a mythical race of lawless giant shepherds who lived in Sicily. They had a single large round eye in the center […]
- Cyclospora infection
Cyclospora infection: Infection with Cyclospora cayetanensis, a single-celled parasite. The first known human cases of illness caused by Cyclospora were reported in 1979. More recently, outbreaks of cyclosporiasis have been reported in the US and Canada. Cyclospora is spread by people ingesting water or food that was contaminated with infected stool. Outbreaks of cyclosporiasis have […]
Cyclosporiasis: Infection with the parasite Cyclospora cayetanensis. See: Cyclospora infection.
Cyclothymia: A form of bipolar disorder in which the mood swings are less severe. See also bipolar disease.
Cylindroma: A benign tumor of skin adnexa such as the sweat gland, arising as a nodule on the scalp and, less often, the face or limbs. Cylindromas may cover the scalp and so are called turban tumors. See: Familial cylindromatosis.