chr2-71669122-C-T

Variant names:

• chr2-71669122-C-T
• rs1280185461
• NM_001130987.2:c.5557C>T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_001130987.2(DYSF):​c.5557C>T​(p.Arg1853Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000562 in 1,601,670 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: DYSF NM_001130987.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:3
• Conservation: PhyloP100: 5.02

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a domain C2 7 (size 148) in uniprot entity DYSF_HUMAN there are 37 pathogenic changes around while only 2 benign (95%) in NM_001130987.2
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.943

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DYSF	NM_001130987.2	c.5557C>T	p.Arg1853Cys	missense_variant	Exon 50 of 56	ENST00000410020.8	NP_001124459.1
DYSF	NM_003494.4	c.5440C>T	p.Arg1814Cys	missense_variant	Exon 49 of 55	ENST00000258104.8	NP_003485.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DYSF	ENST00000410020.8	c.5557C>T	p.Arg1853Cys	missense_variant	Exon 50 of 56	1	NM_001130987.2	ENSP00000386881.3
DYSF	ENST00000258104.8	c.5440C>T	p.Arg1814Cys	missense_variant	Exon 49 of 55	1	NM_003494.4	ENSP00000258104.3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152130 Hom.: 0 Cov.: 33

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000552 AC: 8 AN: 1449540 Hom.: 0 Cov.: 31 AF XY: 0.00000417 AC XY: 3 AN XY: 719360

Gnomad4 AFR exome AF: 0.0000300

Gnomad4 AMR exome AF: 0.0000233

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000240

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000181

Gnomad4 OTH exome AF: 0.0000333

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152130 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74300

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: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Qualitative or quantitative defects of dysferlin Pathogenic:1 Uncertain:1

Nov 19, 2017

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Nov 05, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 1814 of the DYSF protein (p.Arg1814Cys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with DYSF-related conditions (PMID: 21522182, 26404900). ClinVar contains an entry for this variant (Variation ID: 557327). 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 expected to disrupt DYSF protein function with a positive predictive value of 95%. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

not specified Uncertain:1

Oct 11, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: DYSF c.5440C>T (p.Arg1814Cys) results in a non-conservative amino acid change located in the C2 domain (IPR000008) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 233300 control chromosomes. c.5440C>T has been reported in the literature in individuals affected with Limb-Girdle Muscular Dystrophy, Autosomal Recessive (example: Cacciottolo_2011, Magri_2015). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 21522182, 26404900). ClinVar contains an entry for this variant (Variation ID: 557327). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

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

Mar 16, 2018

Counsyl

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.77
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.40
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.94	.;.;.;.;D;.;.;.;.;.;.
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.24	D
MetaRNN	Pathogenic	0.94	D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Pathogenic	3.5	.;.;.;.;M;.;.;.;.;.;.
PrimateAI	Uncertain	0.72	T
PROVEAN	Pathogenic	-7.0	D;D;D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.93
Sift	Pathogenic	0.0	D;D;D;D;D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D;D;D;D;D
Polyphen		1.0	D;D;D;D;D;D;D;D;D;D;D
Vest4		0.96
MutPred		0.76		.;.;.;.;Loss of MoRF binding (P = 0.0103);.;.;.;.;.;.;
MVP		0.98
MPC		0.76
ClinPred		1.0	D
GERP RS		4.5
Varity_R		0.83
gMVP		0.88

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.23		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.23		Position offset: -10

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1280185461; hg19: chr2-71896252;