A novel GNAS1 mutation in a German family with Albright's hereditary osteodystrophy.

Albright's hereditary osteodystrophy (AHO) is an inherited disorder and results from heterozygous loss of function mutation within the human G (s)α gene (GNAS1). AHO appears in two phenotypes, that may occur within the same family. Pseudohypoparathyroidism type Ia (PHP Ia) comprises the clinical features of AHO associated with parathyroid hormone (PTH) resistance while pseudo-pseudohypoparathyroidism (PPHP) includes AHO features without PTH resistance. In the present study we report a mother and a daughter with PPHP and PHP Ia respectively. The 13 exons of GNAS1 were analysed by PCR and direct sequencing. We identified a heterozygous missense mutation in exon 1. This novel mutation results in a stop at codon 35 and a truncated non-functional GNAS1 protein.