X-32644153-G-T

Position:

• chrX-32644153-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_004006.3(DMD):​c.1310C>A​(p.Ala437Asp) variant causes a missense change. The variant allele was found at a frequency of 0.00000183 in 1,094,967 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 1 hemizygotes in GnomAD. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 22)
  • Exomes 𝑓: 0.0000018 (0 hom. 1 hem.)
• Consequence: DMD NM_004006.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 6.81

Genes affected

DMD (HGNC:2928): (dystrophin) This gene spans a genomic range of greater than 2 Mb and encodes a large protein containing an N-terminal actin-binding domain and multiple spectrin repeats. The encoded protein forms a component of the dystrophin-glycoprotein complex (DGC), which bridges the inner cytoskeleton and the extracellular matrix. Deletions, duplications, and point mutations at this gene locus may cause Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), or cardiomyopathy. Alternative promoter usage and alternative splicing result in numerous distinct transcript variants and protein isoforms for this gene. [provided by RefSeq, Dec 2016]

DMD (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.36031675).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DMD	NM_004006.3	c.1310C>A	p.Ala437Asp	missense_variant	11/79	ENST00000357033.9	NP_003997.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DMD	ENST00000357033.9	c.1310C>A	p.Ala437Asp	missense_variant	11/79	1	NM_004006.3	ENSP00000354923.3

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome AF: 0.00000183 AC: 2 AN: 1094967 Hom.: 0 Cov.: 29 AF XY: 0.00000277 AC XY: 1 AN XY: 360583

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000238

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 22

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Duchenne muscular dystrophy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 11, 2021

This sequence change replaces alanine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 437 of the DMD protein (p.Ala437Asp). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with DMD-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Cardiovascular phenotype Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 10, 2024

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.16
BayesDel_addAF	Benign	-0.12	T
BayesDel_noAF	Benign	-0.42
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.24	.;T;.;.;T
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.79	T;.;T;T;T
M_CAP	Benign	0.026	D
MetaRNN	Benign	0.36	T;T;T;T;T
MetaSVM	Benign	-0.81	T
PrimateAI	Uncertain	0.70	T
PROVEAN	Benign	-0.50	.;N;.;N;N
REVEL	Benign	0.17
Sift	Benign	0.56	.;T;.;T;T
Sift4G	Benign	0.55	T;T;T;T;T
Polyphen		0.21, 0.97	.;B;.;.;D
Vest4		0.78
MutPred		0.61		.;.;Gain of disorder (P = 0.022);Gain of disorder (P = 0.022);.;
MVP		0.55
MPC		0.12
ClinPred		0.78	D
GERP RS		5.8
gMVP		0.74

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1556875180; hg19: chrX-32662270;