chr2-190057137-T-C

Position:

• chr2-190057137-T-C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_005259.3(MSTN):​c.*121A>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MSTN NM_005259.3 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.67

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

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.61).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MSTN	NM_005259.3	c.*121A>G		3_prime_UTR_variant	3/3	ENST00000260950.5
C2orf88	XM_047446008.1	c.-517-22817T>C		intron_variant
C2orf88	XM_047446009.1	c.-517-22817T>C		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MSTN	ENST00000260950.5	c.*121A>G		3_prime_UTR_variant	3/3	1	NM_005259.3	P1
C2orf88	ENST00000478197.1	n.220-22086T>C		intron_variant, non_coding_transcript_variant		4
C2orf88	ENST00000495546.1	n.202-22817T>C		intron_variant, non_coding_transcript_variant		4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 12

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Myostatin-related muscle hypertrophy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

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	-0.61
CADD	Benign	14
DANN	Benign	0.84

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

Publications

LitVar

Other links and lift over

dbSNP: rs886055372; hg19: chr2-190921863;