chr15-42387862-C-T

Variant names:

• chr15-42387862-C-T
• rs763719290
• NM_000070.3:c.608C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM5 PP3_Strong

The NM_000070.3(CAPN3):​c.608C>T​(p.Ala203Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,834 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A203G) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: CAPN3 NM_000070.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:4
• Conservation: PhyloP100: 7.91
• Publications: 1 publications found

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]

CAPN3 Gene-Disease associations (from GenCC):

• autosomal recessive limb-girdle muscular dystrophy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• autosomal recessive limb-girdle muscular dystrophy type 2A

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Myriad Women’s Health, Labcorp Genetics (formerly Invitae)
• muscular dystrophy, limb-girdle, autosomal dominant 4

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• muscular dystrophy, limb-girdle, autosomal dominant

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ENSG00000258461 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 20 uncertain in NM_000070.3
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr15-42387862-C-G is described in ClinVar as Pathogenic. ClinVar VariationId is 843051.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.968

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CAPN3	NM_000070.3	c.608C>T	p.Ala203Val	missense_variant	Exon 4 of 24	ENST00000397163.8	NP_000061.1
CAPN3	NM_024344.2	c.608C>T	p.Ala203Val	missense_variant	Exon 4 of 23		NP_077320.1
CAPN3	NM_173087.2	c.608C>T	p.Ala203Val	missense_variant	Exon 4 of 21		NP_775110.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CAPN3	ENST00000397163.8	c.608C>T	p.Ala203Val	missense_variant	Exon 4 of 24	1	NM_000070.3	ENSP00000380349.3
ENSG00000258461	ENST00000495723.1	n.*404C>T		non_coding_transcript_exon_variant	Exon 8 of 26	2		ENSP00000492063.1
ENSG00000258461	ENST00000495723.1	n.*404C>T		3_prime_UTR_variant	Exon 8 of 26	2		ENSP00000492063.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000795 AC: 2 AN: 251458 AF XY: 0.00000736

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461834 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727204

African (AFR) AF: 0.00 AC: 0 AN: 33480

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

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

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

South Asian (SAS) AF: 0.0000464 AC: 4 AN: 86256

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: 0.00000270 AC: 3 AN: 1111956

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:4

Revision: criteria provided, conflicting classifications

Submissions by phenotype

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

Jul 30, 2024

3billion

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is observed at an extremely low frequency in the gnomAD v4.0.0 dataset (total allele frequency: <0.001%). In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.93 (>=0.6, sensitivity 0.68 and specificity 0.92); 3Cnet: 0.92 (>=0.6, sensitivity 0.72 and precision 0.9)]. The same nucleotide change resulting in the same amino acid change has been previously reported to be associated with CAPN3-related disorder (PMID: 35169782 / 3billion dataset). The variant has been reported to be in trans with a pathogenic variant as either compound heterozygous or homozygous in at least one similarly affected unrelated individual (PMID: 35169782 / 3billion dataset). A different missense change at the same codon (p.Ala203Gly) has been reported to be associated with CAPN3-related disorder (ClinVar ID: VCV000843051). Therefore, this variant is classified as likely pathogenic according to the recommendation of ACMG/AMP guideline. -

Dec 13, 2024

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 203 of the CAPN3 protein (p.Ala203Val). This variant is present in population databases (rs763719290, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with CAPN3-related conditions. ClinVar contains an entry for this variant (Variation ID: 289751). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt CAPN3 protein function with a positive predictive value of 80%. This variant disrupts the p.Ala203 amino acid residue in CAPN3. Other variant(s) that disrupt this residue have been determined to be pathogenic (internal data). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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

Jan 27, 2025

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.608C>T (p.Ala203Val) results in a non-conservative amino acid change located in the Calpain domian (Ganaraja_2021) 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 8e-06 in 251458 control chromosomes (gnomAD). c.608C>T has been reported in the literature in individuals affected with Limb-Girdle Muscular Dystrophy, Autosomal Recessive (Ganaraja_2021, Karthikeyan_2024). 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. The following publications have been ascertained in the context of this evaluation (PMID: 35169782, 39548682). ClinVar contains an entry for this variant (Variation ID: 289751). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Inborn genetic diseases Uncertain:1

Jun 18, 2019

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Uncertain:1

Jul 27, 2016

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.91
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.45
CADD	Pathogenic	28
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.54	D;.;.;D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.98
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D;D;D;D
M_CAP	Pathogenic	0.32	D
MetaRNN	Pathogenic	0.97	D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.8	.;H;H;H
PhyloP100		7.9
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-3.9	D;D;D;D
REVEL	Pathogenic	0.93
Sift	Pathogenic	0.0	D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D
Polyphen		1.0	.;D;D;D
Vest4		0.95
MutPred		0.85		Gain of ubiquitination at K207 (P = 0.1375);Gain of ubiquitination at K207 (P = 0.1375);Gain of ubiquitination at K207 (P = 0.1375);Gain of ubiquitination at K207 (P = 0.1375);
MVP		0.99
MPC		0.63
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.96
gMVP		0.85
Mutation Taster		=6/94	disease causing

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

Other links and lift over

dbSNP: rs763719290; hg19: chr15-42680060;