chr20-58840179-G-A

Variant names:

• chr20-58840179-G-A
• rs1230896240
• NM_016592.5:c.73G>A

Variant summary

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

The NM_016592.5(GNAS):​c.73G>A​(p.Gly25Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,459,218 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 Uncertain significance (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GNAS NM_016592.5 missense
• Clinical Significance: Uncertain significance no assertion criteria provided U:1
• Conservation: PhyloP100: 4.10
• Publications: 1 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-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 Gene-Disease associations (from GenCC):

• pseudohypoparathyroidism type 1B

  Inheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ENSG00000293655 (HGNC:):

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, 0.878

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_016592.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GNAS	NM_016592.5	MANE Plus Clinical	c.73G>A	p.Gly25Ser	missense	Exon 1 of 13	NP_057676.1	O95467-1
	GNAS-AS1	NR_185847.1	MANE Select	n.672+1758C>T		intron	N/A
	GNAS	NM_001410912.1		c.-665G>A		5_prime_UTR	Exon 1 of 13	NP_001397841.1	A0A0A0MR13

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GNAS	ENST00000371075.7	TSL:1 MANE Plus Clinical	c.73G>A	p.Gly25Ser	missense	Exon 1 of 13	ENSP00000360115.3	O95467-1
	GNAS	ENST00000313949.11	TSL:1	c.73G>A	p.Gly25Ser	missense	Exon 1 of 13	ENSP00000323571.7	O95467-1
	GNAS	ENST00000453292.7	TSL:5	c.73G>A	p.Gly25Ser	missense	Exon 1 of 12	ENSP00000392000.2	O95467-1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000813 AC: 2 AN: 245866 AF XY: 0.00000745

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000580

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1459218 Hom.: 0 Cov.: 36 AF XY: 0.00000138 AC XY: 1 AN XY: 726082

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.0000447 AC: 2 AN: 44708

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26120

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86244

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50922

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111908

Other (OTH) AF: 0.00 AC: 0 AN: 60372

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
-	1	-	GNAS-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.70
BayesDel_addAF	Uncertain	0.058	T
BayesDel_noAF	Uncertain	0.020
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.58	D
Eigen	Uncertain	0.37
Eigen_PC	Uncertain	0.34
FATHMM_MKL	Benign	0.68	D
LIST_S2	Benign	0.72	T
M_CAP	Benign	0.0054	T
MetaRNN	Pathogenic	0.88	D
MetaSVM	Benign	-0.73	T
MutationAssessor	Benign	1.1	L
PhyloP100		4.1
PrimateAI	Pathogenic	0.81	D
PROVEAN	Benign	-2.2	N
REVEL	Uncertain	0.37
Sift	Pathogenic	0.0	D
Sift4G	Benign	0.34	T
Polyphen		1.0	D
Vest4		0.74
MutPred		0.78		Gain of glycosylation at G25 (P = 0.0141)
MVP		0.73
ClinPred		0.71	D
GERP RS		3.6
PromoterAI		-0.014	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Mutation Taster		=90/10	polymorphism

Splicing

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

Other links and lift over

dbSNP: rs1230896240; hg19: chr20-57415234;