Limb disorders
Gene: GNASComment on mode of inheritance: For the phenotype pseudohypoparathyroidism, monoallelic and imprinted is the appropriate mode of inheritance as indicated. For the phenotype of McCune Albright syndrome, which includes polyostotic fibrous dysplasia, the mechanism is a post-zygotic variant leading to a somatic mosaic picture. The mode of inheritance is therefore still best matched to monoallelic, however depending on the level of mosaicism in the tissue tested, the proportion of alleles with the variant could vary considerably (from 0-50%) and therefore the ability to detect it.Created: 11 Jul 2017, 4:16 p.m.
Listed as associated with Skeletal Dysplasia by Gene Advisor (June 2016), Steve AbbsCreated: 27 Jul 2016, 9:36 a.m.
Comment on mode of inheritance: All monogenic except for ACTH-independent macronodular adrenal hyperplasia 219080 (isolated cases) & McCune-Albright syndrome, 174800 (somatic mosaic)Created: 7 Jul 2016, 11:13 a.m.
Comment on list classification: Used diagnostically by Ana Beleza (Guy's and St Thomas' NHS Foundation Trust)Created: 21 Jun 2016, 12:49 p.m.
Tier 1Created: 17 Jun 2016, 8:04 a.m.
Mode of inheritance
Other - please specify in evaluation comments
Phenotypes
ACTH-independent macronodular adrenal hyperplasia 219080 IC ; McCune-Albright syndrome, somatic, mosaic 174800 ; Osseous heteroplasia, progressive 166350; Pseudohypoparathyroidism Ia 103580; Pseudohypoparathyroidism Ib 603233; Pseudohypoparathyroidism Ic 612462; Pseudopseudohypoparathyroidism 612463
Variants in this GENE are reported as part of current diagnostic practice
Ana Beleza: Tier 1
Expert Review Green was added to GNAS. Panel: Limb disorders Emory Genetics Laboratory was added to GNAS. Panel: Limb disorders Model of inheritance for gene GNAS was set to MONOALLELIC, autosomal or pseudoautosomal, paternally imprinted (maternal allele expressed)
London South East RGC GSTT was added to GNAS. Panel: Limb disorders
GNAS was added to Limb disorders panel. Sources: Viapath
GNAS was created by Ellen McDonagh