rs755849745

Variant names:

• chr2-71564194-TACAG-T
• rs755849745
• NM_001130987.2:c.2550_2553delGACA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001130987.2(DYSF):​c.2550_2553delGACA​(p.Thr851SerfsTer3) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: DYSF NM_001130987.2 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 9.25

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 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-71564194-TACAG-T is Pathogenic according to our data. Variant chr2-71564194-TACAG-T is described in ClinVar as [Pathogenic]. Clinvar id is 496872.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-71564194-TACAG-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DYSF	NM_001130987.2	c.2550_2553delGACA	p.Thr851SerfsTer3	frameshift_variant	Exon 24 of 56	ENST00000410020.8	NP_001124459.1
DYSF	NM_003494.4	c.2496_2499delGACA	p.Thr833SerfsTer3	frameshift_variant	Exon 24 of 55	ENST00000258104.8	NP_003485.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DYSF	ENST00000410020.8	c.2550_2553delGACA	p.Thr851SerfsTer3	frameshift_variant	Exon 24 of 56	1	NM_001130987.2	ENSP00000386881.3
DYSF	ENST00000258104.8	c.2496_2499delGACA	p.Thr833SerfsTer3	frameshift_variant	Exon 24 of 55	1	NM_003494.4	ENSP00000258104.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251488 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135918

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

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: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461894 Hom.: 0 AF XY: 0.00000138 AC XY: 1 AN XY: 727248

Gnomad4 AFR exome AF: 0.00

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Distal myopathy with anterior tibial onset;C1850889:Autosomal recessive limb-girdle muscular dystrophy type 2B;C4551973:Miyoshi muscular dystrophy 1 Pathogenic:1

May 02, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:1

Apr 19, 2017

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Miyoshi muscular dystrophy 1 Pathogenic:1

Jun 13, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Qualitative or quantitative defects of dysferlin Pathogenic:1

Nov 13, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Thr833Serfs*3) in the DYSF gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in DYSF are known to be pathogenic (PMID: 17698709, 20301480). This variant is present in population databases (rs755849745, gnomAD 0.0009%). This premature translational stop signal has been observed in individual(s) with limb-girdle muscular dystrophy and/or Miyoshi myopathy (PMID: 17994539, 21522182). ClinVar contains an entry for this variant (Variation ID: 496872). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

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: rs755849745; hg19: chr2-71791324;