chr20-58840140-C-T

Position:

chr20-58840140-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_StrongPM2PP5_Moderate

The NM_016592.5(GNAS):c.34C>T(p.Arg12Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,611,410 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

GNAS
NM_016592.5 stop_gained

Scores

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 1.19

Variant links:

Genes affected

GNAS (HGNC:4392): (GNAS complex locus) 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 pseudohypoparathyroidism type 1a, pseudohypoparathyroidism type 1b, Albright hereditary osteodystrophy, pseudopseudohypoparathyroidism, McCune-Albright syndrome, progressive osseus heteroplasia, polyostotic fibrous dysplasia of bone, and some pituitary tumors. [provided by RefSeq, Aug 2012]

GNAS links:

GNAS-AS1 (HGNC:24872): (GNAS antisense RNA 1) This gene produces a paternally-imprinted antisense RNA transcript that helps regulate the GNAS complex locus, which encodes the alpha subunit of the stimulatory G protein. Defects in this gene are a cause of pseudohypoparathyroidism type Ib.[provided by RefSeq, Jun 2010]

GNAS-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.954 CDS is truncated, and there are 2 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 20-58840140-C-T is Pathogenic according to our data. Variant chr20-58840140-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3242103.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GNAS	NM_016592.5 linkuse as main transcript	c.34C>T	p.Arg12Ter	stop_gained	1/13	ENST00000371075.7
GNAS-AS1	NR_002785.2 linkuse as main transcript	n.819+1797G>A		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GNAS	ENST00000371075.7 linkuse as main transcript	c.34C>T	p.Arg12Ter	stop_gained	1/13	1	NM_016592.5		O95467-1
GNAS-AS1	ENST00000424094.6 linkuse as main transcript	n.819+1797G>A		intron_variant, non_coding_transcript_variant		1

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152086

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1459324

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726066

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000180

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152086

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74278

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Pseudopseudohypoparathyroidism

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Neuberg Centre For Genomic Medicine, NCGM

The observed stop gain variant c.34C>T (p.Arg12Ter) in GNAS gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. The c.34C>T variant is absent in gnomAD Exomes database. This variant has not been submitted to the ClinVar database. The nucleotide change c.34C>T in GNAS is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. This variant is predicted to cause loss of normal protein function through protein truncation. Mutation taster predicts that this variant is likely to undergo non-sense mediated decay. Loss of function variant in GNAS gene have been reported previously in individuals affected with pseudohypoparathyroidism Ia, pseudopseudohypoparathyroidism, and progressive osseous heteroplasia. Additional studies will be required to prove the pathogenicity of this variant. For these reasons, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.51

BayesDel_noAF

Pathogenic

0.49

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Benign

-0.0039

Eigen_PC

Benign

0.052

FATHMM_MKL

Benign

0.55

MutationTaster

Benign

1.0

A;A;A

Vest4

0.83

GERP RS

3.8

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.6

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over