2-71590277-A-T

Position:

• chr2-71590277-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001130987.2(DYSF):​c.3563A>T​(p.Asp1188Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,876 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 Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: DYSF NM_001130987.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 8.84

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.844

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DYSF	NM_001130987.2	c.3563A>T	p.Asp1188Val	missense_variant	32/56	ENST00000410020.8	NP_001124459.1
DYSF	NM_003494.4	c.3509A>T	p.Asp1170Val	missense_variant	32/55	ENST00000258104.8	NP_003485.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DYSF	ENST00000410020.8	c.3563A>T	p.Asp1188Val	missense_variant	32/56	1	NM_001130987.2	ENSP00000386881.3
DYSF	ENST00000258104.8	c.3509A>T	p.Asp1170Val	missense_variant	32/55	1	NM_003494.4	ENSP00000258104.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251460 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135894

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461876 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727238

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

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

Uncertain significance, no assertion criteria provided

clinical testing

Natera, Inc.

Jun 25, 2021

- -

Qualitative or quantitative defects of dysferlin Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 24, 2021

This sequence change replaces aspartic acid with valine at codon 1170 of the DYSF protein (p.Asp1170Val). The aspartic acid residue is moderately conserved and there is a large physicochemical difference between aspartic acid and valine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with DYSF-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.87
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	0.0
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.80	.;.;.;.;D;.;.;.;.;.;.
Eigen	Pathogenic	0.76
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.27	D
MetaRNN	Pathogenic	0.84	D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	-0.21	T
MutationAssessor	Benign	1.8	.;.;L;.;L;.;.;.;.;.;.
PrimateAI	Uncertain	0.73	T
PROVEAN	Pathogenic	-5.9	D;D;D;D;D;D;D;D;D;D;D
REVEL	Uncertain	0.50
Sift	Uncertain	0.025	D;D;D;D;D;D;D;D;D;D;D
Sift4G	Uncertain	0.0060	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		0.83
MutPred		0.38		.;.;Loss of disorder (P = 0.0067);.;Loss of disorder (P = 0.0067);.;.;.;.;.;.;
MVP		0.85
MPC		0.74
ClinPred		0.99	D
GERP RS		5.6
Varity_R		0.55
gMVP		0.68

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.10		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: rs1442583354; hg19: chr2-71817407;