2-190057131-A-G

Variant names:

• chr2-190057131-A-G
• rs923518162
• NM_005259.3:c.*127T>C

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_005259.3(MSTN):​c.*127T>C variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000848 in 943,300 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000063 (0 hom.)
• Consequence: MSTN NM_005259.3 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.682
• Publications: 0 publications found

Genes affected

MSTN (HGNC:4223): (myostatin) This gene encodes a secreted ligand of the TGF-beta (transforming growth factor-beta) superfamily of proteins. Ligands of this family bind various TGF-beta receptors leading to recruitment and activation of SMAD family transcription factors that regulate gene expression. The encoded preproprotein is proteolytically processed to generate each subunit of the disulfide-linked homodimer. This protein negatively regulates skeletal muscle cell proliferation and differentiation. Mutations in this gene are associated with increased skeletal muscle mass in humans and other mammals. [provided by RefSeq, Jul 2016]

C2orf88 (HGNC:28191): (chromosome 2 open reading frame 88) Predicted to enable protein kinase A regulatory subunit binding activity. Predicted to be located in plasma membrane. [provided by Alliance of Genome Resources, Apr 2022]

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 (BayesDel_noAF=-0.44).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MSTN	NM_005259.3	c.*127T>C		3_prime_UTR_variant	Exon 3 of 3	ENST00000260950.5	NP_005250.1
AKAP19	XM_047446008.1	c.-517-22823A>G		intron_variant	Intron 2 of 6		XP_047301964.1
AKAP19	XM_047446009.1	c.-517-22823A>G		intron_variant	Intron 1 of 5		XP_047301965.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MSTN	ENST00000260950.5	c.*127T>C		3_prime_UTR_variant	Exon 3 of 3	1	NM_005259.3	ENSP00000260950.3
C2orf88	ENST00000478197.1	n.220-22092A>G		intron_variant	Intron 1 of 1	4
C2orf88	ENST00000495546.1	n.202-22823A>G		intron_variant	Intron 1 of 2	4

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152048 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.0000441

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000632 AC: 5 AN: 791252 Hom.: 0 Cov.: 11 AF XY: 0.00000490 AC XY: 2 AN XY: 408482

African (AFR) AF: 0.00 AC: 0 AN: 18846

American (AMR) AF: 0.0000745 AC: 2 AN: 26840

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 18316

East Asian (EAS) AF: 0.00 AC: 0 AN: 33724

South Asian (SAS) AF: 0.00 AC: 0 AN: 58528

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 44922

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 2744

European-Non Finnish (NFE) AF: 0.00000545 AC: 3 AN: 550038

Other (OTH) AF: 0.00 AC: 0 AN: 37294

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152048 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74264

African (AFR) AF: 0.00 AC: 0 AN: 41422

American (AMR) AF: 0.00 AC: 0 AN: 15208

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5196

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10618

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

European-Non Finnish (NFE) AF: 0.0000441 AC: 3 AN: 67990

Other (OTH) AF: 0.00 AC: 0 AN: 2088

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000416

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Myostatin-related muscle hypertrophy Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.44
CADD	Benign	10
DANN	Benign	0.83
PhyloP100		0.68

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs923518162; hg19: chr2-190921857;