Apert syndrome: A malformation syndrome characterized by a high short skull, underdevelopment of the midface, soft tissue and bony (“mitten glove”) fusion of fingers and toes, fusion of the neck vertebrae, and varying degrees of developmental delay/mental retardation. The frequency of the syndrome rises with the age of the father reflecting the fact that the mutation rate among males rises with their age. Moreover, the mutation that causes Apert syndrome affords the sperm a selective advantage. The mutation is in the gene for fibroblast growth factor receptor 2 (FGFR2) on chromosome 10. Different mutations in FGFR2 are also responsible for two other similar genetic diseases, namely, Pfeiffer syndrome and Crouzon syndrome. See also: Acrocephalosyndactyly.
- Apert syndrome acrocephalosyndactyly
Apert syndrome acrocephalosyndactyly: An inherited disorder causing abnormalities of the skull, face and hands and feet. There is premature closure of some of the sutures of the skull (craniosynostosis) resulting in an abnormally shaped head (which is unusually tall but short from front-to-back) and an abnormally shaped face (with shallow eye sockets and underdevelopment of […]
Apex: The Latin word for summit, the apex is the tip of a pyramidal or rounded structure, such as the lung or the heart. The apex of the lung is indeed its tip’its rounded most superior portion. The apex of the heart is likewise its tip, but it is formed by the left ventricle, so […]
Apgar: Abbreviation for the Apgar score, a practical method of evaluating the physical condition of a newborn infant shortly after delivery. The Apgar score is a number arrived at by scoring the heart rate, respiratory effort, muscle tone, skin color, and response to a catheter in the nostril. Each of these objective signs can receive […]
- Apgar score
An objective score of the condition of a baby after birth. This score is determined by scoring the heart rate, respiratory effort, muscle tone, skin color, and response to a catheter in the nostril. Each of these objective signs receives 0, 1, or 2 points. An Apgar score of 10 means an infant is in […]
Aphakia: Absence or loss of the eye’s natural crystalline lens, as after cataract removal. From a-, without + phacos, the Greek word for a lentil bean. The ancients thought (quite correctly) that the lens of the eye was shaped like a lentil bean.