20-58840129-A-G

Variant names:

• chr20-58840129-A-G
• rs1225314176
• NM_016592.5:c.23A>G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_016592.5(GNAS):​c.23A>G​(p.Gln8Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,459,304 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/15 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: GNAS NM_016592.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.54

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-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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.15258741).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GNAS	NM_016592.5	c.23A>G	p.Gln8Arg	missense_variant	Exon 1 of 13	ENST00000371075.7	NP_057676.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GNAS	ENST00000371075.7	c.23A>G	p.Gln8Arg	missense_variant	Exon 1 of 13	1	NM_016592.5	ENSP00000360115.3
GNAS	ENST00000453292.7	c.23A>G	p.Gln8Arg	missense_variant	Exon 1 of 12	5		ENSP00000392000.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459304 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 726038

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.42
CADD	Benign	20
DANN	Benign	0.97
DEOGEN2	Uncertain	0.44	T;T;T
Eigen	Benign	-0.32
Eigen_PC	Benign	-0.23
FATHMM_MKL	Benign	0.50	N
LIST_S2	Benign	0.46	.;.;T
M_CAP	Benign	0.0035	T
MetaRNN	Benign	0.15	T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.81	L;L;L
PrimateAI	Uncertain	0.63	T
PROVEAN	Benign	-0.90	N;N;N
REVEL	Benign	0.18
Sift	Benign	0.086	T;T;T
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		0.17	B;B;B
Vest4		0.25
MutPred		0.53		Gain of solvent accessibility (P = 0.1071);Gain of solvent accessibility (P = 0.1071);Gain of solvent accessibility (P = 0.1071);
MVP		0.082
ClinPred		0.13	T
GERP RS		2.5

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs1225314176; hg19: chr20-57415184;