Cyclopia (named after the Greek mythology character cyclopes) is the most extreme form of holoprosencephaly and is a congenital disorder (birth defect) characterized by the failure of the embryonic prosencephalon to properly divide the orbits of the eye into two cavities. Its incidence is 1 in 16,000 in born animals and 1 in 200 in miscarried fetuses. Signs and symptoms
Typically, the nose is either missing or not functional. This deformity (called proboscis) forms above the center eye and is characteristic of a form of cyclopia called rhinencephaly or rhinocephaly. Most such embryos are either naturally aborted or are stillborn upon delivery. Although cyclopia is rare, several cyclopic human babies are preserved in medical museums (e.g. The Vrolik Museum, Amsterdam, Trivandrum Medical College).Some extreme cases of cyclopia have been documented in farm animals (horses, sheep, pigs, and sometimes chickens). In such cases, the nose and mouth fail to form, or the nose grows from the roof of the mouth, obstructing airflow and resulting in suffocation shortly after birth. Causes
Genetic defects or toxins can misdirect the embryonic forebrain-dividing process. One highly teratogenic alkaloid toxin that can cause cyclopia is cyclopamine or 2-deoxyjervine, found in the plant Veratrum californicum (also known as corn lily or false hellebore). Grazing animals are most likely to ingest this plant and induce cyclopia in offspring.
Reports of the case were made in the Mercure de France and an illustration of the infant was made by Marie Bihéron. The case was also mentioned in Volume IV of Buffons LHistoire Naturelle. On 1 March 1793, a 46-year-old woman in Boalts Torp, Glimåkra, Sweden gave birth to a child with cyclopia that died after two hours. The child was 35 cm long, its face without nose and nostrils, and its lidless eye with no eyebrow sat raised on the middle of its forehead like a large blueberry. The wrists were somewhat crooked as well as the right foot which was completely crooked and bent inwards. It was not clear whether it was a boy or a girl, but it was believed to be the former. On December 28, 2005, a kitten with cyclopia, "Cy", was born in Redmond, Oregon, United States and died about one day after birth. In 2006, a baby girl in India with cyclopia was born. Her only eye was in the center of her forehead. She did not have a nose and her brain did not separate into two separate hemispheres (holoprosencephaly). The child died one day after her birth. In 2011, an albino cyclops shark fetus was discovered in the body of a caught shark in Mexico, with no discernible nose and one giant eye. The unborn fetus was turned over for medical studies. On October 10, 2012, a small kitten was born.