chr15-42387763-A-G

Position:

• chr15-42387763-A-G

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1 PM2 PP3_Strong PP5_Very_Strong

The ENST00000397163.8(CAPN3):​c.509A>G​(p.Tyr170Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000186 in 1,614,204 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 (★★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CAPN3 ENST00000397163.8 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 6.09

Genes affected

CAPN3 (HGNC:1480): (calpain 3) Calpain, a heterodimer consisting of a large and a small subunit, is a major intracellular protease, although its function has not been well established. This gene encodes a muscle-specific member of the calpain large subunit family that specifically binds to titin. Mutations in this gene are associated with limb-girdle muscular dystrophies type 2A. Alternate promoters and alternative splicing result in multiple transcript variants encoding different isoforms and some variants are ubiquitously expressed. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in ENST00000397163.8
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.978
• PP5: Variant 15-42387763-A-G is Pathogenic according to our data. Variant chr15-42387763-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 557074.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr15-42387763-A-G is described in Lovd as [Likely_pathogenic]. Variant chr15-42387763-A-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CAPN3	NM_000070.3	c.509A>G	p.Tyr170Cys	missense_variant	4/24	ENST00000397163.8	NP_000061.1
CAPN3	NM_024344.2	c.509A>G	p.Tyr170Cys	missense_variant	4/23		NP_077320.1
CAPN3	NM_173087.2	c.509A>G	p.Tyr170Cys	missense_variant	4/21		NP_775110.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CAPN3	ENST00000397163.8	c.509A>G	p.Tyr170Cys	missense_variant	4/24	1	NM_000070.3	ENSP00000380349	P2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152206 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000192

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

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251474 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135908

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: 0.00000137 AC: 2 AN: 1461880 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727242

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000656 AC: 1 AN: 152324 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74494

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2A Pathogenic:3

Likely pathogenic, criteria provided, single submitter	research	Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard	Apr 11, 2024	The p.Tyr170Cys variant in CAPN3 was identified by our study in 2 siblings with autosomal recessive limb-girdle muscular dystrophy, in the compound heterozygous state along with another pathogenic variant. The phase of these variants are unknown at this time. The p.Tyr170Cys variant has also been reported in 4 individuals with limb-girdle muscular dystrophy (PMID: 18055493, 23821418, 25135358), and has been identified in 0.002% (1/44892) of East Asian chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP: rs1555420468). Although this variant has been seen in the general population in a heterozygous state, its frequency is low enough to be consistent with a recessive carrier frequency. This variant has also been reported in ClinVar (Variation ID: 557074) and has been interpreted as likely pathogenic by Counsyl and pathogenic by Invitae. Of the five affected individuals, four were compound heterozygotes that carried a reported pathogenic variant with unknown phase, which increases the likelihood that the p.Tyr170Cys variant is pathogenic (Variation ID: 17621, 283259; (PMID: 18055493, 23821418, 25135358). Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic for autosomal recessive limb-girdle muscular dystrophy. ACMG/AMP Criteria applied: PM3_strong, PP3_moderate, PM2_supporting (Richards 2015). -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Mar 07, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 31, 2022	For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 557074). This missense change has been observed in individual(s) with autosomal recessive limb-girdle muscular dystrophy (PMID: 18055493, 23821418, 25135358, 31127727; external communication). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 170 of the CAPN3 protein (p.Tyr170Cys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.59
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.37
CADD	Pathogenic	31
DANN	Uncertain	1.0
DEOGEN2	Benign	0.34	T;.;.;D
Eigen	Pathogenic	0.83
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.90	D;D;D;D
M_CAP	Pathogenic	0.33	D
MetaRNN	Pathogenic	0.98	D;D;D;D
MetaSVM	Pathogenic	0.81	D
MutationAssessor	Uncertain	2.4	.;M;M;M
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-7.0	D;D;D;D
REVEL	Pathogenic	0.93
Sift	Uncertain	0.0020	D;D;D;D
Sift4G	Uncertain	0.0020	D;D;D;D
Polyphen		1.0	.;D;D;D
Vest4		0.92
MutPred		0.90		Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);
MVP		0.97
MPC		0.71
ClinPred		0.99	D
GERP RS		6.0
Varity_R		0.95
gMVP		0.81

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: rs1555420468; hg19: chr15-42679961;