Genetic Variant NM_004006.3:c.2726C>T (chrX-32484996-G-A) – ACMG Classification: Likely_benign (-4 pts)

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BS2

The NM_004006.3(DMD):c.2726C>T(p.Ala909Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000992 in 1,209,570 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 4 hemizygotes in GnomAD. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000018 ( 0 hom., 1 hem., cov: 23)

Exomes 𝑓: 0.0000091 ( 0 hom. 3 hem. )

Consequence

DMD
NM_004006.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 7.27

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

BS2

High Hemizygotes in GnomAdExome4 at 3 XL gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DMD	NM_004006.3 link	c.2726C>T	p.Ala909Val	missense_variant	Exon 21 of 79	ENST00000357033.9	NP_003997.2	P11532

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DMD	ENST00000357033.9 link	c.2726C>T	p.Ala909Val	missense_variant	Exon 21 of 79	1	NM_004006.3	ENSP00000354923.3		A0A075B6G3

Frequencies

GnomAD3 genomes

AF:

0.0000179

AC:

AN:

111818

Hom.:

Cov.:

AF XY:

0.0000294

AC XY:

AN XY:

33976

show subpopulations

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:

0.0000376

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000546

AC:

AN:

183314

Hom.:

AF XY:

0.00

AC XY:

AN XY:

67788

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000122

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000911

AC:

AN:

1097752

Hom.:

Cov.:

AF XY:

0.00000826

AC XY:

AN XY:

363150

show subpopulations

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:

0.0000107

Gnomad4 OTH exome

AF:

0.0000217

GnomAD4 genome

AF:

0.0000179

AC:

AN:

111818

Hom.:

Cov.:

AF XY:

0.0000294

AC XY:

AN XY:

33976

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000376

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000264

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000149

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Duchenne muscular dystrophy;C0878544:Cardiomyopathy;C0917713:Becker muscular dystrophy;na:Dystrophin deficiency

Uncertain:1

Sep 21, 2018

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Duchenne muscular dystrophy;C0917713:Becker muscular dystrophy;C3668940:Dilated cardiomyopathy 3B

Uncertain:1

Dec 28, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Duchenne muscular dystrophy

Uncertain:1

Aug 14, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 909 of the DMD protein (p.Ala909Val). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with DMD-related conditions. ClinVar contains an entry for this variant (Variation ID: 455884). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt DMD protein function with a negative predictive value of 95%. 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

Uncertain:1

Jun 14, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.A909V variant (also known as c.2726C>T), located in coding exon 21 of the DMD gene, results from a C to T substitution at nucleotide position 2726. The alanine at codon 909 is replaced by valine, an amino acid with similar properties. Based on data from gnomAD, the T allele has an overall frequency of 0.001% (2/205351) total alleles studied, with 0 hemizygote(s) observed. The highest observed frequency was 0.002% (2/92705) of European (non-Finnish) alleles. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.19

BayesDel_addAF

Benign

-0.084

BayesDel_noAF

Benign

-0.36

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.30

.;T;.;.

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.88

D;.;D;D

M_CAP

Uncertain

0.11

MetaRNN

Uncertain

0.58

D;D;D;D

MetaSVM

Benign

-0.82

PrimateAI

Uncertain

0.62

PROVEAN

Benign

-1.4

.;N;.;N

REVEL

Benign

0.18

Sift

Benign

0.10

.;T;.;T

Sift4G

Benign

0.15

T;T;T;T

Polyphen

1.0

.;D;.;.

Vest4

0.61

MVP

0.69

MPC

0.11

ClinPred

0.74

GERP RS

5.1

gMVP

0.19

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over