X-32463509-G-C

Position:

• chrX-32463509-G-C

Variant summary

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

The NM_004006.3(DMD):​c.3362C>G​(p.Pro1121Arg) variant causes a missense change. The variant allele was found at a frequency of 0.000000916 in 1,091,507 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples 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: 23)
  • Exomes 𝑓: 9.2e-7 (0 hom. 0 hem.)
• Consequence: DMD NM_004006.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.61

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]

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=0.42151588).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DMD	NM_004006.3	c.3362C>G	p.Pro1121Arg	missense_variant	25/79	ENST00000357033.9	NP_003997.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DMD	ENST00000357033.9	c.3362C>G	p.Pro1121Arg	missense_variant	25/79	1	NM_004006.3	ENSP00000354923.3

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome AF: 9.16e-7 AC: 1 AN: 1091507 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 357693

Gnomad4 AFR exome AF: 0.0000380

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Duchenne muscular dystrophy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 18, 2021

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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with DMD-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces proline with arginine at codon 1121 of the DMD protein (p.Pro1121Arg). The proline residue is highly conserved and there is a moderate physicochemical difference between proline and arginine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Benign	-0.15	T
BayesDel_noAF	Benign	-0.46
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Benign	0.33	.;T;.;.
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.88	D;.;D;D
M_CAP	Uncertain	0.13	D
MetaRNN	Benign	0.42	T;T;T;T
MetaSVM	Benign	-0.80	T
PrimateAI	Benign	0.43	T
PROVEAN	Uncertain	-4.1	.;D;.;D
REVEL	Benign	0.21
Sift	Uncertain	0.0050	.;D;.;D
Sift4G	Uncertain	0.045	D;D;D;D
Polyphen		0.77	.;P;.;.
Vest4		0.42
MutPred		0.44		.;.;Loss of glycosylation at P1121 (P = 0.0301);Loss of glycosylation at P1121 (P = 0.0301);
MVP		0.45
MPC		0.12
ClinPred		0.96	D
GERP RS		4.6
gMVP		0.16

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: rs1557369441; hg19: chrX-32481626;