20-58839812-C-A

Variant names:

• chr20-58839812-C-A
• rs61558260
• NM_016592.5:c.-295C>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_016592.5(GNAS):​c.-295C>A variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 585,224 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000023 (0 hom.)
• Consequence: GNAS NM_016592.5 5_prime_UTR
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.886
• Publications: 7 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: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.8).

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.-295C>A		5_prime_UTR	Exon 1 of 13	NP_057676.1	O95467-1
	GNAS-AS1	NR_185847.1	MANE Select	n.672+2125G>T		intron	N/A
	GNAS	NM_001410912.1		c.-1032C>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.-295C>A		5_prime_UTR	Exon 1 of 13	ENSP00000360115.3	O95467-1
	GNAS	ENST00000313949.11	TSL:1	c.-295C>A		5_prime_UTR	Exon 1 of 13	ENSP00000323571.7	O95467-1
	GNAS-AS1	ENST00000718285.1	MANE Select	n.672+2125G>T		intron	N/A

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152196 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

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: 0.00000231 AC: 1 AN: 433028 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 226596

African (AFR) AF: 0.00 AC: 0 AN: 12168

American (AMR) AF: 0.00 AC: 0 AN: 16200

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 13502

East Asian (EAS) AF: 0.00 AC: 0 AN: 30278

South Asian (SAS) AF: 0.00 AC: 0 AN: 41942

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 29370

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 1910

European-Non Finnish (NFE) AF: 0.00000381 AC: 1 AN: 262302

Other (OTH) AF: 0.00 AC: 0 AN: 25356

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152196 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74360

African (AFR) AF: 0.00 AC: 0 AN: 41432

American (AMR) AF: 0.0000654 AC: 1 AN: 15288

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4836

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68038

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 9

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.80
CADD	Benign	11
DANN	Benign	0.72
PhyloP100		0.89
PromoterAI		-0.041	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		0.99

Splicing

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

Other links and lift over

dbSNP: rs61558260; hg19: chr20-57414867;