chr20-58840129-A-G

Variant names:

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

Variant summary

Our verdict is Uncertain significance. The variant received 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. 14/18 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q8P) has been classified as Uncertain significance.

• 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
• Publications: 2 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 0 ACMG points.

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

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.23A>G	p.Gln8Arg	missense	Exon 1 of 13	NP_057676.1	O95467-1
	GNAS-AS1	NR_185847.1	MANE Select	n.672+1808T>C		intron	N/A
	GNAS	NM_001410912.1		c.-715A>G		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.23A>G	p.Gln8Arg	missense	Exon 1 of 13	ENSP00000360115.3	O95467-1
	GNAS	ENST00000313949.11	TSL:1	c.23A>G	p.Gln8Arg	missense	Exon 1 of 13	ENSP00000323571.7	O95467-1
	GNAS	ENST00000453292.7	TSL:5	c.23A>G	p.Gln8Arg	missense	Exon 1 of 12	ENSP00000392000.2	O95467-1

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

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50894

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111978

Other (OTH) AF: 0.00 AC: 0 AN: 60374

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.22
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.42
CADD	Benign	20
DANN	Benign	0.97
DEOGEN2	Uncertain	0.44	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
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.81	L
PhyloP100		1.5
PrimateAI	Uncertain	0.63	T
PROVEAN	Benign	-0.90	N
REVEL	Benign	0.18
Sift	Benign	0.086	T
Sift4G	Pathogenic	0.0	D
Polyphen		0.17	B
Vest4		0.25
MutPred		0.53		Gain of solvent accessibility (P = 0.1071)
MVP		0.082
ClinPred		0.13	T
GERP RS		2.5
PromoterAI		0.019	Neutral
Mutation Taster		=94/6	polymorphism

Splicing

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

Other links and lift over

dbSNP: rs1225314176; hg19: chr20-57415184;