[MIM 103 580]

Very rare. Autosomal dominant transmission influenced by the sex. Form of pseudohypoparathyroidism (type Ia or Ic) caused by mutations of the GNAS1 gene (20q13.32) coding for a membrane stimulating G protein. Albright syndrome appears if the mutation is inherited from the mother. In case of mutation inherited from the father, the child suffers from pseudopseudohypoparathyroidism, presenting the same clinical picture as Albright syndrome but without resistance to PTH and so with normal blood levels of Ca and PO4.

The classic signs are:

-         a short stature

-         moderate obesity

-         a round face with a short neck

-         mild mental impairment

-         tooth enamel dysplasia

-         osteoporosis, short metacarpals, cone-shaped epiphyses

-         cutaneous or subcutaneous calcifications

-         sometimes abnormalities of the cervical vertebrae

-         a subcapsular cataract.

Given that the G protein encoded by GNAS1 is also involved in the process of response to other hormones, there is sometimes an underactive thyroid gland and associated gonadal failure.

Biology: hypocalcemia, hyperphosphatemia, high levels of parathyroid hormone. In childhood, hypocalcemia can cause attacks of tetany, muscle cramps or convulsions.

 Anesthetic implications: 

check calcemia, avoid hyperventilation. Make sure that there are no other associated endocrine abnormalities. Obesity.

References : 

Updated: December 2019