rs1064794020

Variant names:

• chr2-71679173-C-T
• rs1064794020
• NM_001130987.2:c.6001C>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001130987.2(DYSF):​c.6001C>T​(p.Gln2001*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,798 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 Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: DYSF NM_001130987.2 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 7.91
• Publications: 6 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

ACMG classification

Our verdict: Pathogenic. The variant received 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 2-71679173-C-T is Pathogenic according to our data. Variant chr2-71679173-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 419655.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DYSF	NM_001130987.2	c.6001C>T	p.Gln2001*	stop_gained	Exon 53 of 56	ENST00000410020.8	NP_001124459.1
DYSF	NM_003494.4	c.5884C>T	p.Gln1962*	stop_gained	Exon 52 of 55	ENST00000258104.8	NP_003485.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DYSF	ENST00000410020.8	c.6001C>T	p.Gln2001*	stop_gained	Exon 53 of 56	1	NM_001130987.2	ENSP00000386881.3
DYSF	ENST00000258104.8	c.5884C>T	p.Gln1962*	stop_gained	Exon 52 of 55	1	NM_003494.4	ENSP00000258104.3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461798 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727198

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111952

Other (OTH) AF: 0.00 AC: 0 AN: 60382

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

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:2

May 14, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 16, 2023

Kariminejad - Najmabadi Pathology & Genetics Center

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PVS1(Very Strong),PP5,PM2 -

not provided Pathogenic:2

May 04, 2021

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 26, 2018

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Q1962X nonsense variant in the DYSF gene has been reported previously in two brothers with dysferlinopathywho were compound heterozygous for Q1962X and another DYSF variant (Rosales et al.,2010). One study indicated Q1962X induced a large splicing change, though in silico algorithms do notpredict Q1962X affects splicing (Xiong et al., 2014). This variant is predicted to cause loss of normalprotein function either through protein truncation or nonsense-mediated mRNA decay. The Q1962Xvariant was not observed in approximately 6500 individuals of European and African American ancestryin the NHLBI Exome Sequencing Project, indicating it is not a common variant in these populations. Weinterpret Q1962X as a pathogenic variant. -

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

Jul 28, 2017

Counsyl

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

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

Sep 18, 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.Gln1962*) 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 not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with DYSF-related conditions (PMID: 20544924). ClinVar contains an entry for this variant (Variation ID: 419655). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	53
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.99
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		7.9
Vest4		0.90
GERP RS		5.3
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.33		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.33		Position offset: -20

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

Other links and lift over

dbSNP: rs1064794020; hg19: chr2-71906303;