2-71454017-C-T

Position:

• chr2-71454017-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_003494.4(DYSF):​c.19C>T​(p.Leu7Phe) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,854 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: DYSF NM_003494.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.09

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]

ENSG00000289327 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM1: In a domain C2 1 (size 100) in uniprot entity DYSF_HUMAN there are 7 pathogenic changes around while only 0 benign (100%) in NM_003494.4
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2564088).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DYSF	NM_003494.4	c.19C>T	p.Leu7Phe	missense_variant	1/55	ENST00000258104.8	NP_003485.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DYSF	ENST00000258104.8	c.19C>T	p.Leu7Phe	missense_variant	1/55	1	NM_003494.4	ENSP00000258104.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251038 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135802

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461854 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727228

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Qualitative or quantitative defects of dysferlin Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 06, 2022

This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 7 of the DYSF protein (p.Leu7Phe). 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 DYSF-related conditions. 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	Benign	0.32
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.31
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.44	.;.;.;.;T
Eigen	Benign	-0.049
Eigen_PC	Benign	0.055
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Uncertain	0.94	D;D;D;D;D
M_CAP	Benign	0.044	D
MetaRNN	Benign	0.26	T;T;T;T;T
MetaSVM	Benign	-0.65	T
MutationAssessor	Benign	1.9	M;M;M;M;M
MutationTaster	Benign	1.0	N;N;N;N;N
PROVEAN	Benign	-0.86	N;N;N;N;N
REVEL	Benign	0.13
Sift	Benign	0.10	T;T;T;T;T
Sift4G	Benign	0.15	T;T;T;T;T
Polyphen		0.21	B;B;B;B;B
Vest4		0.28
MutPred		0.56		Loss of stability (P = 0.2006);Loss of stability (P = 0.2006);Loss of stability (P = 0.2006);Loss of stability (P = 0.2006);Loss of stability (P = 0.2006);
MVP		0.66
ClinPred		0.64	D
GERP RS		4.1
Varity_R		0.50

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: rs1373048381; hg19: chr2-71681147; COSMIC: COSV50572359;