Hypoparathyroidism Familial Isolated

A rare heterogeneous group of metabolic disorders with abnormal calcium metabolism due to deficient secretion of parathormone (PTH) without other endocrine disorders or developmental defects. It can occur at any age (from the newborn period to adulthood) but generally starts within the first decade of life. The disease may be due to an activating mutation of the calcium-sensing receptor (CASR) gene. This is the most common genetic cause and is transmitted as an autosomal dominant trait. It represents 42% of isolated hypoparathyroidism cases. Thirteen mutations have been described in familial or sporadic cases. In three families, mutations in the PTH gene have been identified. One family has been reported with a mutation in the gene encoding the glial cells missing homolog b (GCMB) transcription factor.