chr15-42386185-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 6 ACMG points: 6P and 0B. PP3PP4PM3_Strong

This summary comes from the ClinGen Evidence Repository: The NM_000070.3: c.398C>T variant in CAPN3 is a missense variant predicted to cause substitution of alanine by valine at position 133, p.(Ala133Val). This variant has been reported in two unrelated individuals with a clinical diagnosis of LGMD, where it was confirmed in trans with a likely pathogenic or pathogenic variant (c.598_612del p.(Phe200_Leu204del), 1.0 pt x2, PMID:16141003, LOVD individuals #00214184, #00214185; PM3_Strong, PP4). However, it has also been observed in a homozygous state or in trans with a second presumed diagnostic CAPN3 variant (c.133G>A p.(Ala45Thr), c.1303G>A (p.Glu435Lys)) in three individuals without a clear LGMD phenotype (ClinVar SCV001985435.3, SCV003509679.1 internal data communication). The filtering allele frequency of this variant is 0.0001855 (the upper threshold of the 95% CI of 16/86246 exome chromosomes) in the South Asian population in gnomAD v4.1.0, which is greater than the ClinGen LGMD VCEP threshold (≤0.0001) (PM2_Supporting not met). Of note, the South Asian population also includes one homozygous individual of unknown age. The computational predictor REVEL gives a score of 0.959, which is above the LGMD VCEP threshold of ≥0.70, evidence that correlates with impact to CAPN3 function (PP3). In summary, while 6 Bayesian points were awarded to this variant based on the ACMG/AMP criteria applied, as specified by the ClinGen LGMD VCEP (PM3_Strong, PP3, PP4), given the conflicting evidence, the VCEP has opted to classify it as a variant of uncertain significance for autosomal recessive limb girdle muscular dystrophy (LGMD VCEP specifications version 1.0.0; 03/25/2025). LINK:https://erepo.genome.network/evrepo/ui/classification/CA7511008/MONDO:0015152/187

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000021 ( 1 hom. )

Consequence

CAPN3
NM_000070.3 missense

Scores

13
5
1

Clinical Significance

Uncertain significance reviewed by expert panel U:9

Conservation

PhyloP100: 7.91
Variant links:
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]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 6 ACMG points.

PM3
For more information check the summary or visit ClinGen Evidence Repository.
PP3
For more information check the summary or visit ClinGen Evidence Repository.
PP4
For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CAPN3NM_000070.3 linkc.398C>T p.Ala133Val missense_variant Exon 3 of 24 ENST00000397163.8 NP_000061.1 P20807-1
CAPN3NM_024344.2 linkc.398C>T p.Ala133Val missense_variant Exon 3 of 23 NP_077320.1 P20807-3
CAPN3NM_173087.2 linkc.398C>T p.Ala133Val missense_variant Exon 3 of 21 NP_775110.1 P20807-2
LOC105370794XR_932178.3 linkn.-154G>A upstream_gene_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CAPN3ENST00000397163.8 linkc.398C>T p.Ala133Val missense_variant Exon 3 of 24 1 NM_000070.3 ENSP00000380349.3 P20807-1
ENSG00000258461ENST00000495723.1 linkn.*194C>T non_coding_transcript_exon_variant Exon 7 of 26 2 ENSP00000492063.1 A0A1W2PQD3
ENSG00000258461ENST00000495723.1 linkn.*194C>T 3_prime_UTR_variant Exon 7 of 26 2 ENSP00000492063.1 A0A1W2PQD3

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152190
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000597
AC:
15
AN:
251410
Hom.:
0
AF XY:
0.0000662
AC XY:
9
AN XY:
135870
show subpopulations
Gnomad AFR exome
AF:
0.000123
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.000229
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000440
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000212
AC:
31
AN:
1461364
Hom.:
1
Cov.:
31
AF XY:
0.0000220
AC XY:
16
AN XY:
727050
show subpopulations
Gnomad4 AFR exome
AF:
0.0000598
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.000186
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000630
Gnomad4 OTH exome
AF:
0.0000662
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152190
Hom.:
0
Cov.:
32
AF XY:
0.0000404
AC XY:
3
AN XY:
74348
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000207
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000668
Hom.:
0
Bravo
AF:
0.0000227
ExAC
AF:
0.0000412
AC:
5
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:9
Revision: reviewed by expert panel
LINK: link

Submissions by phenotype

not provided Uncertain:4
Feb 07, 2025
GeneDx
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Identified in a patient with limb-girdle muscular dystrophy who also harbored a second variant in CAPN3, however, it is unknown if these variants were on the same (in cis) or opposite (in trans) CAPN3 allele (PMID: 16141003); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 16141003) -

-
Breakthrough Genomics, Breakthrough Genomics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: not provided

- -

Sep 14, 2016
Eurofins Ntd Llc (ga)
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

May 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

CAPN3: PM2, PM3:Supporting, PP3 -

Autosomal recessive limb-girdle muscular dystrophy type 2A Uncertain:3
Jun 10, 2021
Genome-Nilou Lab
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jul 07, 2017
Counsyl
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Oct 05, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 133 of the CAPN3 protein (p.Ala133Val). This variant is present in population databases (rs774685118, gnomAD 0.02%). This missense change has been observed in individual(s) with clinical features of autosomal recessive limb-girdle muscular dystrophy (PMID: 16141003). ClinVar contains an entry for this variant (Variation ID: 290335). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CAPN3 protein function. 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. -

not specified Uncertain:1
Oct 03, 2022
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: CAPN3 c.398C>T (p.Ala133Val) results in a non-conservative amino acid change located in the catalytic domain (IPR001300) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 6e-05 in 251410 control chromosomes (gnomAD). This frequency is not higher than the estimated maximum expected for a pathogenic variant in CAPN3 causing Limb-Girdle Muscular Dystrophy, Autosomal Recessive (0.0032), allowing no conclusion about variant significance. The variant, c.398C>T, has been reported in the literature in 2 individuals affected with Limb-Girdle Muscular Dystrophy, who were described as compound heterozygotes, however no 2nd variant was specified (Piluso_2005). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014, and all of them classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Autosomal recessive limb-girdle muscular dystrophy Uncertain:1
Mar 25, 2025
ClinGen Limb Girdle Muscular Dystrophy Variant Curation Expert Panel, ClinGen
Significance: Uncertain significance
Review Status: reviewed by expert panel
Collection Method: curation

The NM_000070.3: c.398C>T variant in CAPN3 is a missense variant predicted to cause substitution of alanine by valine at position 133, p.(Ala133Val). This variant has been reported in two unrelated individuals with a clinical diagnosis of LGMD, where it was confirmed in trans with a likely pathogenic or pathogenic variant (c.598_612del p.(Phe200_Leu204del), 1.0 pt x2, PMID: 16141003, LOVD individuals #00214184, #00214185; PM3_Strong, PP4). However, it has also been observed in a homozygous state or in trans with a second presumed diagnostic CAPN3 variant (c.133G>A p.(Ala45Thr), c.1303G>A (p.Glu435Lys)) in three individuals without a clear LGMD phenotype (ClinVar SCV001985435.3, SCV003509679.1 internal data communication). The filtering allele frequency of this variant is 0.0001855 (the upper threshold of the 95% CI of 16/86246 exome chromosomes) in the South Asian population in gnomAD v4.1.0, which is greater than the ClinGen LGMD VCEP threshold (≤0.0001) (PM2_Supporting not met). Of note, the South Asian population also includes one homozygous individual of unknown age. The computational predictor REVEL gives a score of 0.959, which is above the LGMD VCEP threshold of ≥0.70, evidence that correlates with impact to CAPN3 function (PP3). In summary, while 6 Bayesian points were awarded to this variant based on the ACMG/AMP criteria applied, as specified by the ClinGen LGMD VCEP (PM3_Strong, PP3, PP4), given the conflicting evidence, the VCEP has opted to classify it as a variant of uncertain significance for autosomal recessive limb girdle muscular dystrophy (LGMD VCEP specifications version 1.0.0; 03/25/2025). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.97
BayesDel_addAF
Pathogenic
0.38
D
BayesDel_noAF
Pathogenic
0.60
CADD
Pathogenic
31
DANN
Pathogenic
1.0
DEOGEN2
Uncertain
0.52
D;.;.;D
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Uncertain
0.93
D;D;D;D
M_CAP
Pathogenic
0.64
D
MetaRNN
Pathogenic
0.97
D;D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
3.8
.;H;H;H
PrimateAI
Uncertain
0.78
T
PROVEAN
Uncertain
-3.8
D;D;D;D
REVEL
Pathogenic
0.96
Sift
Pathogenic
0.0
D;D;D;D
Sift4G
Pathogenic
0.0
D;D;D;D
Polyphen
1.0
.;D;D;D
Vest4
0.76
MutPred
0.92
Gain of loop (P = 0.2045);Gain of loop (P = 0.2045);Gain of loop (P = 0.2045);Gain of loop (P = 0.2045);
MVP
0.98
MPC
0.63
ClinPred
0.98
D
GERP RS
6.1
Varity_R
0.91
gMVP
0.86

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs774685118; hg19: chr15-42678383; API