Intellectual disability - microarray and sequencing
Gene: GNASComment on mode of inheritance: Disease causing variants in the GNAS locus have differing expression panels. Pseudohypothyroidism Ia & Ic are all caused by GNAS variants arising in the maternal alleles, therefore, the mode of inheritance (MOI) for GNAS in these conditions should be monoallelic maternally imprinted. Pseudopseudohypoparathyroidism, OMIM:612463 is associated with variants in the paternal alleles therefore, the mode of inheritance for GNAS in this condition should be monoallelic paternally imprinted. Because intellectual disability is seen in these phenotypes, the MOI has been set to monoallelic, imprinted status unknown.Created: 13 Oct 2022, 2:22 p.m. | Last Modified: 13 Oct 2022, 2:22 p.m.
Panel Version: 3.1745
This is a pertinent gene from the NIHR BioResource - Rare Diseases Study (NIHRBR-RD) BRIDGE Study : SPEED (Specialist Pathology: Evaluating Exomes in Diagnostics) which covers epilepsies, movement and microcephaly disorders, this gene is on the SPEED_NEURO_20170705 gene list. Evidences used for SPEED NEURO gene list: in_ddg2p_20141118_conf;in_ddg2p_20141118_conf;in_ddg2p_201507;in_ddg2p_201507_conf;in_ddg2p_2_4_2017;in_ddg2p_2_4_2017_conf;in_gilissen_2014_known;in_UKGTN_v12 . Main mutation mechanism : Activating; Loss of functionCreated: 27 Jul 2017, 6:21 p.m.
Evidences key, gene present in following gene lists and main mutation mechanism : ddg2p_20141118; ddg2p_20141118_conf; ddg2p_201507; ddg2p_201507_conf; gilissen_2014_known; sfari_20150206; UKGTN_v12; Nijmegen_ID_diagnostic; Nijmegen_ID_candidates; GEL_ID_green_20160217; neuro_20160418_strict; Activating; Loss of function. This is a pertinent gene from the BRIDGE Study : SPEED (Specialist Pathology: Evaluating Exomes in Diagnostics) which covers epilepsies, movement and microcephaly disorders, this gene comes from the SPEED_NEURO_v3.0_20170404 gene list. The following experts from the BRIDGE consortium NIHRBR-RD contributed to this panel: - Professor F. Lucy Raymond, Cambridge Institute for Medical Research, University of Cambridge - Manju Kurian, Paediatric neurologist, Great Ormond Street Hosptial - Keren Carss, NIHR BioResource - Rare Diseases, Cambridge University Hospitals NHS Foundation Trust - Alba Sanchis-Juan, NIHR BioResource - Rare Diseases, Cambridge University Hospitals NHS Foundation Trust - Marie Erwood NIHR BioResource - Rare Diseases, Cambridge University Hospitals NHS Foundation Trust - Louise Daugherty, NIHR BioResource - Rare Diseases, Cambridge University Hospitals NHS Foundation TrustCreated: 19 Jul 2017, 12:34 p.m.
Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown
Publications
Mode of pathogenicity
Comment on mode of inheritance: Changed from 'other' to monoallelic, to allow variants to be tiered within this gene. Loss of function mutations on the maternal allele cause pseudohypoparathyroidism type Ia; loss of function mutations on the paternal allele cause pseudopseudohypoparathyroidism, so the imprinted allele can change.Created: 9 May 2017, 2:43 p.m.
Added 'mosaicism' tag to reflect reviewer's comment.Created: 5 Apr 2017, 6:08 a.m.
Mechanism: MosaicCreated: 16 Nov 2015, 11:25 a.m.
Mode of inheritance
Other - please specify in evaluation comments
Phenotypes
ACTH-INDEPENDENT MACRONODULAR ADRENAL HYPERPLASIA (AIMAH)
Publications
Phenotypes for gene: GNAS were changed from Pseudohypoparathyroidism Ia, 103580McCune-Albright syndrome, 174800Pseudohypoparathyroidism Ic, 612462Osseous heteroplasia, progressive, 166350Pseudohypoparathyroidism Ib, 603233Prolonged bleeding time, brachydactyly and mental retardationAcromegaly, 102200Pseudopseudohypoparathyroidism, 612463Prolonged bleeding time, brachydactyly, and mental retardationACTH-independent macronodular adrenal hyperplasia, 219080; ACTH-INDEPENDENT MACRONODULAR ADRENAL HYPERPLASIA (AIMAH) to Pseudohypoparathyroidism Ia, OMIM:103580; pseudohypoparathyroidism type 1A, MONDO:0007078; Pseudohypoparathyroidism Ic, OMIM:612462; pseudohypoparathyroidism type 1C, MONDO:0012911; Pseudopseudohypoparathyroidism, OMIM:612463; pseudopseudohypoparathyroidism, MONDO:0012912
Mode of inheritance for gene: GNAS was changed from MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown
Source Victorian Clinical Genetics Services was added to GNAS.
12.03.2018: Due to major updates completed (Phase 1, 2 and 3), this panel was promoted to Version 2 in order to reflect the major updates since November 2017 which have resulted in reviews for 836 genes added by Genomics England Curators and the Clinical Team, 130 new Green genes added to the interpretation pipeline (from 751 to 881 Green genes), and the gene total has increased from 1879 to 1927.
Mode of inheritance for GNAS was changed to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown
The Gel status was updated for this whole panel
The Gel status was updated for this whole panel
GNAS was added to Intellectual disabilitypanel. Source: Expert Review Green Model of inheritance for gene GNAS was set to Other - please specify in evaluation comments
GNAS was added to Intellectual disabilitypanel. Sources: Radboud University Medical Center, Nijmegen