CUTANEOUS OSSIFICATION AND ALBRIGHTS HERE DITARY OSTEODYSTROPHY

Albright's hereditary osteodystrophy has been diagnosed in a 35-year-o ld woman who presented recurrent cutaneous ossifications of the auricu lar area. The patient exhibited other cutaneous ossifications, a short stature with obesity, round face, stocky hands and feet, radiological calcifications of the skull and of the hands, cataract, auditive impa irment and dental abnormalities. Serum calcium, phosphorus and parathy roid hormone levels were normal. Urine excretion of phosphorus and cyc lic adenosine monophosphate (cAMP) markedly increased after intravenou s injection of parathyroid hormone, referring to pseudopseudohypoparat hyroidism. Albright's hereditary osteodystrophy is associated either w ith pseudohppoparathyroidism type la characterized by parathyroid horm one and other hormones resistance or with pseudopseudohypoparathyroidi sm without hormone resistance. This two conditions are considered vari ants of the same defect of the stimulatory G protein of adenylate cycl ase which is necessary for the action of parathyroid hormone, and othe r hormones to use cAMP as an intracellular second messenger. But Albri ght's hereditary osteodystrophy may be associated with other biochemic al abnormalities, such as defect of catalytic activity of adenylate cy clase in pseudohypoparathyroidism type 1c. There is an important varia bility of the clinical, biochemical and genetical expression of pseudo hypoparathyroidism and today classification is provisional.