Brachydactyly type B
Overview
Anonychia onychodystrophy brachydactyly type b: A rare, dominantly inherited disorder characterized abnormal or absent nails, permanently flexed fingers and a broad, finger-like thumb.
Symptoms
* Broad thumbs * Finger-like thumbs * Camptodactyly * Absent nails * Abnormal nails * Long thumbs * Underdeveloped hand bones - metatarasals * Underdeveloped foot bones - metatacarpals * Underdeveloped hand bones - metatarasals * Underdeveloped end bones in fingers * Underdeveloped end bones in toes
Causes
Parathyroid hormone is a hormone produced by the parathyroid glands that helps regulate calcium and phosphate levels in the blood. The effects of PTH are seen in several body systems including the skeletal, gastrointestinal, renal (kidney), muscular, and central nervous system. In pseudohypoparathyroidism, there is enough PTH, but the body cannot respond to it. The body is "resistant" to the effects of PTH. As a result, pseudohypoparathyroidism is very similar to hypoparathyroidism, with low calcium levels and high phosphate levels in the blood. This results in the characteristic symptoms which are generally first seen in childhood.