Background:  

    This locus has a highly complex imprinted expression pattern. It gives rise to maternally, paternally, and 

    biallelically expressed transcripts that are derived from four alternative promoters and 5' exons. Some 

    transcripts contain a differentially methylated region (DMR) at their 5' exons, and this DMR is commonly found 

    in imprinted genes and correlates with transcript expression. An antisense transcript is produced from an 

    overlapping locus on the opposite strand. One of the transcripts produced from this locus, and the antisense

    transcript, are paternally expressed noncoding RNAs, and may regulate imprinting in this region. In addition,

    one of the transcripts contains a second overlapping ORF, which encodes a structurally unrelated protein - Alex.

    Alternative splicing of downstream exons is also observed, which results in different forms of the stimulatory

    G-protein alpha subunit, a key element of the classical signal transduction pathway linking receptor-ligand

    interactions with the activation of adenylyl cyclase and a variety of cellular reponses. Multiple transcript variants 

    encoding different isoforms have been found for this gene. Mutations in this gene result in pseudohypoparath

    yroidism type 1a, pseudohypoparathyroidism type 1b, Albright hereditary osteodystrophy, pseudopseudohy

    poparathyroidism, McCune-Albright syndrome, progressive osseus heteroplasia, polyostotic fibrous dysplasia of 

    bone, and some pituitary tumors.