2-210293802-T-C

Position:

• chr2-210293802-T-C

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1_Strong PM2 PP3_Strong PP5

The NM_079420.3(MYL1):​c.479-2A>G variant causes a splice acceptor change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 33)
• Consequence: MYL1 NM_079420.3 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 7.84

Genes affected

MYL1 (HGNC:7582): (myosin light chain 1) Myosin is a hexameric ATPase cellular motor protein. It is composed of two heavy chains, two nonphosphorylatable alkali light chains, and two phosphorylatable regulatory light chains. This gene encodes a myosin alkali light chain expressed in fast skeletal muscle. Two transcript variants have been identified for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.13162394 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.5, offset of -19, new splice context is: catggccttctttctgaaAGgag. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: BayesDel_addAF computational evidence supports a deleterious effect, 0.425
• PP5: Variant 2-210293802-T-C is Pathogenic according to our data. Variant chr2-210293802-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 627413.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr2-210293802-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYL1	NM_079420.3	c.479-2A>G		splice_acceptor_variant		ENST00000352451.4
MYL1	NM_079422.3	c.347-2A>G		splice_acceptor_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYL1	ENST00000352451.4	c.479-2A>G		splice_acceptor_variant		1	NM_079420.3
MYL1	ENST00000341685.8	c.347-2A>G		splice_acceptor_variant		1		P1
MYL1	ENST00000484290.1	n.610-2A>G		splice_acceptor_variant, non_coding_transcript_variant		5
MYL1	ENST00000496436.5	n.582-2A>G		splice_acceptor_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Congenital myopathy with reduced type 2 muscle fibers Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jul 16, 2024

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.37
CADD	Pathogenic	35
DANN	Uncertain	0.99
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	D;D
GERP RS		5.9

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.97		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.67		Position offset: 17
DS_AL_spliceai		0.97		Position offset: -2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1559659233; hg19: chr2-211158526; COSMIC: COSV58974603;