chr20-58886254-C-T

Position:

• chr20-58886254-C-T

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 2P and 8B. PM2 BP4_Strong BS1

The NM_016592.5(GNAS):​c.*43-9358C>T variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00202 in 152,244 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 0.0020 (0 hom., cov: 33)
• Consequence: GNAS NM_016592.5 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.198

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]

(HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.86).
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00202 (307/152244) while in subpopulation AFR AF= 0.00686 (285/41522). AF 95% confidence interval is 0.00621. There are 0 homozygotes in gnomad4. There are 141 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GNAS	NM_016592.5	c.*43-9358C>T		intron_variant		ENST00000371075.7
GNAS	NM_080425.4	c.2069-9358C>T		intron_variant		ENST00000371100.9
LOC101927932	NR_126334.1	n.37+2520G>A		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GNAS	ENST00000371075.7	c.*43-9358C>T		intron_variant		1	NM_016592.5
GNAS	ENST00000371100.9	c.2069-9358C>T		intron_variant		5	NM_080425.4
	ENST00000441270.6	n.19+2520G>A		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes AF: 0.00199 AC: 303 AN: 152126 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00676

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000983

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00316

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00192

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome AF: 0.00202 AC: 307 AN: 152244 Hom.: 0 Cov.: 33 AF XY: 0.00189 AC XY: 141 AN XY: 74446

Gnomad4 AFR AF: 0.00686

Gnomad4 AMR AF: 0.000981

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.00190

Alfa AF: 0.00229 Hom.: 0

Bravo AF: 0.00216

Asia WGS AF: 0.00173 AC: 7 AN: 3478

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.86
CADD	Benign	2.5
DANN	Benign	0.55

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs6026577; hg19: chr20-57461309;