G protein G_sα (GNAS1), the probable candidate gene for albright hereditary osteodystrophy, is assigned to human chromosome 20q12-q13.2

Guanine nucleotide-binding proteins, also known as G proteins, mediate intracellular responses to a wide variety of extracellular stimuli. A variety of genes that specify the synthesis of the components of guanine nucleotide proteins have been identified. One of these proteins, termed G_sα (GNAS1), is the G protein component of the olfactory signal transduction cascade. Mutations in the GNAS1 gene leading to G_sα protein deficiency are known to be associated with pseudohypoparathyroidism Ia (Albright hereditary esteodystrophy) and certain pituitary tumors with acromegaly. Studies on the human-mouse somatic cell hybrids provisionally assigned this gene to chromosome 20. We have now confirmed this localization on chromosome 20 and regionally assigned the GNAS1 gene to 20q12-q13.2 by in situ hybridization.