rs727503915

Positions:

• chr2-71669208-G-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1_Moderate PM2 PP5_Very_Strong

The NM_001130987.2(DYSF):​c.5642+1G>A variant causes a splice donor change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: DYSF NM_001130987.2 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 9.91

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 Pathogenic. Variant got 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.0149371065 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-71669208-G-A is Pathogenic according to our data. Variant chr2-71669208-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 167030.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-71669208-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DYSF	NM_001130987.2	c.5642+1G>A		splice_donor_variant		ENST00000410020.8	NP_001124459.1
DYSF	NM_003494.4	c.5525+1G>A		splice_donor_variant		ENST00000258104.8	NP_003485.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DYSF	ENST00000258104.8	c.5525+1G>A		splice_donor_variant		1	NM_003494.4	ENSP00000258104	A1
DYSF	ENST00000410020.8	c.5642+1G>A		splice_donor_variant		1	NM_001130987.2	ENSP00000386881	A1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

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

Nov 08, 2022

Variant summary: DYSF c.5525+1G>A is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a canonical 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant was absent in 228924 control chromosomes. c.5525+1G>A has been reported in the literature in individuals affected with Limb-Girdle Muscular Dystrophy and Miyoshi myopathy (Cacciottolo_2011, Walter_2013), with one family reported as compound heterozygous, carrying a second (likely) pathogenic variant. These data indicate that the variant is likely associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, classifying the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Jan 23, 2014

- -

Miyoshi muscular dystrophy 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Dec 28, 2022

- -

Qualitative or quantitative defects of dysferlin Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 10, 2022

For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the DYSF protein in which other variant(s) (p.Asp1837Asn) have been determined to be pathogenic (PMID: 11257469, 22194990). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. Studies have shown that disruption of this splice site results in skipping of exon 49, but is expected to preserve the integrity of the reading-frame (PMID: 21522182). ClinVar contains an entry for this variant (Variation ID: 167030). Disruption of this splice site has been observed in individual(s) with DYSF-related conditions (PMID: 21522182). This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 49 of the DYSF gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in a shortened protein product. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	34
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D;D
GERP RS		5.4

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.75		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.75		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs727503915; hg19: chr2-71896338;