rs886042296

Variant names:

• chr15-42387754-T-C
• rs886042296
• NM_000070.3:c.500T>C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000070.3(CAPN3):​c.500T>C​(p.Phe167Ser) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CAPN3 NM_000070.3 missense, splice_region
• Scores: Splicing: ADA: 0.9185
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:3
• Conservation: PhyloP100: 8.02

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]

ENSG00000258461 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a strand (size 7) in uniprot entity CAN3_HUMAN there are 7 pathogenic changes around while only 0 benign (100%) in NM_000070.3
• PM2: Very rare variant in population databases, with high coverage
• 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.500T>C	p.Phe167Ser	missense_variant, splice_region_variant	Exon 4 of 24	ENST00000397163.8	NP_000061.1
CAPN3	NM_024344.2	c.500T>C	p.Phe167Ser	missense_variant, splice_region_variant	Exon 4 of 23		NP_077320.1
CAPN3	NM_173087.2	c.500T>C	p.Phe167Ser	missense_variant, splice_region_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.500T>C	p.Phe167Ser	missense_variant, splice_region_variant	Exon 4 of 24	1	NM_000070.3	ENSP00000380349.3
ENSG00000258461	ENST00000495723.1	n.*296T>C		splice_region_variant, non_coding_transcript_exon_variant	Exon 8 of 26	2		ENSP00000492063.1
ENSG00000258461	ENST00000495723.1	n.*296T>C		3_prime_UTR_variant	Exon 8 of 26	2		ENSP00000492063.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000468 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1 Uncertain:2

Jul 20, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Seen with a second CAPN3 variant, phase unknown, in a patient with clinically suspected limb-girdle muscular dystrophy type 2A (PMID: 25079074); Not observed at significant frequency in large population cohorts (gnomAD); 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: 25079074) -

Mar 01, 2024

CeGaT Center for Human Genetics Tuebingen

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

CAPN3: PM2, PM3, PP3 -

May 16, 2017

Eurofins Ntd Llc (ga)

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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

Dec 18, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces phenylalanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 167 of the CAPN3 protein (p.Phe167Ser). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with autosomal recessive limb-girdle muscular dystrophy (PMID: 25079074). ClinVar contains an entry for this variant (Variation ID: 282048). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. Studies have shown that this missense change does not significantly alter or has an unclear effect on CAPN3 gene expression (PMID: 25079074). 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	1.0
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.68	D;.;.;D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.99
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.93	D;D;D;D
M_CAP	Pathogenic	0.69	D
MetaRNN	Pathogenic	0.97	D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.4	.;H;H;H
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-6.8	D;D;D;D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0	.;D;D;D
Vest4		0.92
MutPred		0.83		Loss of catalytic residue at F167 (P = 0.0799);Loss of catalytic residue at F167 (P = 0.0799);Loss of catalytic residue at F167 (P = 0.0799);Loss of catalytic residue at F167 (P = 0.0799);
MVP		0.99
MPC		0.85
ClinPred		1.0	D
GERP RS		6.0
Varity_R		0.99
gMVP		0.94

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.92
dbscSNV1_RF	Benign	0.44
SpliceAI score (max)		0.13		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: rs886042296; hg19: chr15-42679952;