chr20-58903532-G-A

Variant names:

• chr20-58903532-G-A
• rs587778381
• ENST00000676826.2:c.2191G>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The ENST00000676826.2(GNAS):​c.2191G>A​(p.Glu731Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: GNAS ENST00000676826.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1 O:1
• Conservation: PhyloP100: 7.79
• Publications: 14 publications found

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 Gene-Disease associations (from GenCC):

• McCune-Albright syndrome

  Inheritance: AD, Unknown Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics
• progressive osseous heteroplasia

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE, NO_KNOWN Submitted by: G2P, Orphanet, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• pseudohypoparathyroidism type 1B

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Orphanet
• pseudohypoparathyroidism type 1C

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Orphanet
• pseudopseudohypoparathyroidism

  Inheritance: AD, Mitochondrial Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Orphanet
• pseudohypoparathyroidism type 1A

  Inheritance: Mitochondrial, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.9

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GNAS	NM_080425.4	c.2188G>A	p.Glu730Lys	missense_variant, splice_region_variant	Exon 4 of 13	ENST00000371100.9	NP_536350.2
GNAS	NM_000516.7	c.259G>A	p.Glu87Lys	missense_variant, splice_region_variant	Exon 4 of 13	ENST00000371085.8	NP_000507.1
GNAS	NM_016592.5	c.*165G>A		3_prime_UTR_variant	Exon 4 of 13	ENST00000371075.7	NP_057676.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GNAS	ENST00000676826.2	c.2191G>A	p.Glu731Lys	missense_variant	Exon 4 of 13			ENSP00000504675.2
GNAS	ENST00000371102.8	c.2146G>A	p.Glu716Lys	missense_variant	Exon 3 of 12	5		ENSP00000360143.4
GNAS	ENST00000354359.12	c.262G>A	p.Glu88Lys	missense_variant	Exon 4 of 13	1		ENSP00000346328.7
GNAS	ENST00000371095.7	c.217G>A	p.Glu73Lys	missense_variant	Exon 3 of 12	1		ENSP00000360136.3
GNAS	ENST00000470512.6	c.85G>A	p.Glu29Lys	missense_variant	Exon 4 of 13	5		ENSP00000499552.2
GNAS	ENST00000480232.6	c.85G>A	p.Glu29Lys	missense_variant	Exon 5 of 14	5		ENSP00000499545.2
GNAS	ENST00000663479.2	c.85G>A	p.Glu29Lys	missense_variant	Exon 4 of 13			ENSP00000499353.2
GNAS	ENST00000462499.6	c.40G>A	p.Glu14Lys	missense_variant	Exon 3 of 12	2		ENSP00000499758.2
GNAS	ENST00000467227.6	c.40G>A	p.Glu14Lys	missense_variant	Exon 4 of 13	3		ENSP00000499681.2
GNAS	ENST00000478585.6	c.40G>A	p.Glu14Lys	missense_variant	Exon 3 of 12	2		ENSP00000499762.2
GNAS	ENST00000481039.6	c.40G>A	p.Glu14Lys	missense_variant	Exon 3 of 12	5		ENSP00000499767.2
GNAS	ENST00000485673.6	c.40G>A	p.Glu14Lys	missense_variant	Exon 3 of 12	5		ENSP00000499334.2
GNAS	ENST00000488546.6	c.40G>A	p.Glu14Lys	missense_variant	Exon 3 of 12	5		ENSP00000499332.2
GNAS	ENST00000492907.6	c.40G>A	p.Glu14Lys	missense_variant	Exon 3 of 12	3		ENSP00000499443.2
GNAS	ENST00000371100.9	c.2188G>A	p.Glu730Lys	missense_variant, splice_region_variant	Exon 4 of 13	5	NM_080425.4	ENSP00000360141.3
GNAS	ENST00000371085.8	c.259G>A	p.Glu87Lys	missense_variant, splice_region_variant	Exon 4 of 13	1	NM_000516.7	ENSP00000360126.3
GNAS	ENST00000371075.7	c.*165G>A		3_prime_UTR_variant	Exon 4 of 13	1	NM_016592.5	ENSP00000360115.3
GNAS	ENST00000461152.6	c.*129G>A		3_prime_UTR_variant	Exon 3 of 3	5		ENSP00000499274.1
GNAS	ENST00000453292.7	c.*120G>A		3_prime_UTR_variant	Exon 3 of 12	5		ENSP00000392000.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Nov 25, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 87 of the GNAS protein (p.Glu87Lys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with GNAS-related conditions. ClinVar contains an entry for this variant (Variation ID: 134474). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not specified Other:1

Sep 19, 2013

ITMI

Significance: not provided

Review Status: no classification provided

Collection Method: reference population

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.70
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.38
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.89	D;.;.;.;.;D;.;.;T
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.91	D;D;T;D;D;D;T;T;D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.90	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.7	.;.;.;.;.;H;.;.;.
PhyloP100		7.8
PrimateAI	Pathogenic	0.79	T
PROVEAN	Uncertain	-3.5	D;N;D;.;N;D;D;D;.
REVEL	Pathogenic	0.85
Sift	Uncertain	0.0020	D;D;D;.;T;D;D;D;.
Sift4G	Uncertain	0.030	D;D;T;T;T;T;D;D;T
Polyphen		0.91	P;.;.;.;.;P;.;P;.
Vest4		0.70
MutPred		0.63		Gain of MoRF binding (P = 0.0041);.;.;.;.;.;.;.;.;
MVP		0.99
MPC		1.2
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.85
gMVP		0.92
Mutation Taster		=36/64	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs587778381; hg19: chr20-57478587;