2-71453721-G-C

Variant names:

• chr2-71453721-G-C
• rs1477070599
• NM_003494.4:c.-278G>C

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_Strong BS1_Supporting BS2

The NM_003494.4(DYSF):​c.-278G>C variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000401 in 515,622 control chromosomes in the GnomAD database, including 4 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00051 (4 hom.)
• Consequence: DYSF NM_003494.4 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.255
• Publications: 0 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

ENSG00000289327 (HGNC:):

ACMG classification

Our verdict: Benign. The variant received -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.68).
• BS1: Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.000131 (20/152240) while in subpopulation EAS AF = 0.00368 (19/5160). AF 95% confidence interval is 0.00241. There are 0 homozygotes in GnomAd4. There are 13 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High Homozygotes in GnomAdExome4 at 4 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DYSF	NM_003494.4	c.-278G>C		5_prime_UTR_variant	Exon 1 of 55	ENST00000258104.8	NP_003485.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DYSF	ENST00000258104.8	c.-278G>C		5_prime_UTR_variant	Exon 1 of 55	1	NM_003494.4	ENSP00000258104.3

Frequencies

GnomAD3 genomes AF: 0.000131 AC: 20 AN: 152122 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00367

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.000515 AC: 187 AN: 363382 Hom.: 4 Cov.: 0 AF XY: 0.000533 AC XY: 102 AN XY: 191304

African (AFR) AF: 0.00 AC: 0 AN: 10558

American (AMR) AF: 0.00 AC: 0 AN: 15932

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 11072

East Asian (EAS) AF: 0.00771 AC: 185 AN: 24004

South Asian (SAS) AF: 0.00 AC: 0 AN: 44010

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 21332

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 1544

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 214086

Other (OTH) AF: 0.0000960 AC: 2 AN: 20844

GnomAD4 genome AF: 0.000131 AC: 20 AN: 152240 Hom.: 0 Cov.: 32 AF XY: 0.000175 AC XY: 13 AN XY: 74440

African (AFR) AF: 0.0000241 AC: 1 AN: 41542

American (AMR) AF: 0.00 AC: 0 AN: 15304

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00368 AC: 19 AN: 5160

South Asian (SAS) AF: 0.00 AC: 0 AN: 4808

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10630

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68004

Other (OTH) AF: 0.00 AC: 0 AN: 2116

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.68
CADD	Benign	11
DANN	Benign	0.82
PhyloP100		-0.26
PromoterAI		-0.026	Neutral

Splicing

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

Other links and lift over

dbSNP: rs1477070599; hg19: chr2-71680851;