2-71454015-T-A

Variant names:

• chr2-71454015-T-A
• rs1354334539
• NM_003494.4:c.17T>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_003494.4(DYSF):​c.17T>A​(p.Ile6Asn) variant causes a missense change. The variant allele was found at a frequency of 0.0000137 in 1,461,860 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. I6I) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000014 (0 hom.)
• Consequence: DYSF NM_003494.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 4.15
• Publications: 3 publications found

Genes affected

DYSF (HGNC:3097): (dysferlin) The protein encoded by this gene belongs to the ferlin family and is a skeletal muscle protein found associated with the sarcolemma. It is involved in muscle contraction and contains C2 domains that play a role in calcium-mediated membrane fusion events, suggesting that it may be involved in membrane regeneration and repair. In addition, the protein encoded by this gene binds caveolin-3, a skeletal muscle membrane protein which is important in the formation of caveolae. Specific mutations in this gene have been shown to cause autosomal recessive limb girdle muscular dystrophy type 2B (LGMD2B) as well as Miyoshi myopathy. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2008]

DYSF Gene-Disease associations (from GenCC):

• autosomal recessive limb-girdle muscular dystrophy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• neuromuscular disease caused by qualitative or quantitative defects of dysferlin

  Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
• autosomal recessive limb-girdle muscular dystrophy type 2B

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
• distal myopathy with anterior tibial onset

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• congenital myopathy, Paradas type

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Miyoshi myopathy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000289327 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.782

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DYSF	NM_003494.4	c.17T>A	p.Ile6Asn	missense_variant	Exon 1 of 55	ENST00000258104.8	NP_003485.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DYSF	ENST00000258104.8	c.17T>A	p.Ile6Asn	missense_variant	Exon 1 of 55	1	NM_003494.4	ENSP00000258104.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.0000137 AC: 20 AN: 1461860 Hom.: 0 Cov.: 31 AF XY: 0.0000110 AC XY: 8 AN XY: 727228

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000180 AC: 20 AN: 1112000

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:3

Jun 20, 2019

Revvity Omics, Revvity

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

May 24, 2017

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 10, 2025

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Identified with a second DYSF variant, phase unknown, in an individual with progressive muscle weakness and loss of ambulation; however dysferlin levels on muscle biopsy were outside of the disease-associated range (PMID: 36983702); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 24438169, 36983702) -

Autosomal recessive limb-girdle muscular dystrophy type 2B Uncertain:1

Sep 16, 2020

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Neuromuscular disease caused by qualitative or quantitative defects of dysferlin Uncertain:1

Jul 18, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with asparagine, which is neutral and polar, at codon 6 of the DYSF protein (p.Ile6Asn). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with DYSF-related conditions. ClinVar contains an entry for this variant (Variation ID: 502095). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt DYSF protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Uncertain	0.067	T
BayesDel_noAF	Benign	-0.14
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.86	.;.;.;.;D
Eigen	Benign	0.15
Eigen_PC	Benign	0.15
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Uncertain	0.95	D;D;D;D;D
M_CAP	Uncertain	0.26	D
MetaRNN	Pathogenic	0.78	D;D;D;D;D
MetaSVM	Benign	-0.29	T
MutationAssessor	Pathogenic	3.0	M;M;M;M;M
PhyloP100		4.1
PROVEAN	Uncertain	-3.1	D;D;D;D;D
REVEL	Uncertain	0.49
Sift	Uncertain	0.0010	D;D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D
Polyphen		0.62	P;P;P;P;P
Vest4		0.68
MVP		0.69
ClinPred		0.98	D
GERP RS		3.0
PromoterAI		0.024	Neutral
Varity_R		0.95
Mutation Taster		=49/51	disease causing

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

Other links and lift over

dbSNP: rs1354334539; hg19: chr2-71681145;