rs1555421875

Variant names:

• chr15-42399632-G-A
• rs1555421875
• NM_000070.3:c.1334G>A

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_000070.3(CAPN3):​c.1334G>A​(p.Gly445Glu) variant causes a missense 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. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G445R) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: CAPN3 NM_000070.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 10.0

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 Pathogenic. Variant got 10 ACMG points.

• PM1: In a region_of_interest Domain III (size 168) in uniprot entity CAN3_HUMAN there are 132 pathogenic changes around while only 0 benign (100%) in NM_000070.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr15-42399631-G-A is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CAPN3	NM_000070.3	c.1334G>A	p.Gly445Glu	missense_variant	Exon 10 of 24	ENST00000397163.8	NP_000061.1
CAPN3	NM_024344.2	c.1334G>A	p.Gly445Glu	missense_variant	Exon 10 of 23		NP_077320.1
CAPN3	NM_173087.2	c.1190G>A	p.Gly397Glu	missense_variant	Exon 9 of 21		NP_775110.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CAPN3	ENST00000397163.8	c.1334G>A	p.Gly445Glu	missense_variant	Exon 10 of 24	1	NM_000070.3	ENSP00000380349.3
ENSG00000258461	ENST00000495723.1	n.*1130G>A		non_coding_transcript_exon_variant	Exon 14 of 26	2		ENSP00000492063.1
ENSG00000258461	ENST00000495723.1	n.*1130G>A		3_prime_UTR_variant	Exon 14 of 26	2		ENSP00000492063.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Oct 17, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. This variant disrupts the p.Gly445 amino acid residue in CAPN3. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10330340, 15221789, 17236769, 18854869). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. ClinVar contains an entry for this variant (Variation ID: 468642). This variant has not been reported in the literature in individuals affected with CAPN3-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 445 of the CAPN3 protein (p.Gly445Glu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.70	D;.;.;D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D;D
M_CAP	Pathogenic	0.76	D
MetaRNN	Pathogenic	0.99	D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.2	.;H;.;H
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-7.8	.;D;D;D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	.;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D
Polyphen		1.0, 1.0	.;D;D;D
Vest4		0.95
MutPred		0.97		.;Loss of catalytic residue at C447 (P = 0.0765);.;Loss of catalytic residue at C447 (P = 0.0765);
MVP		0.99
MPC		0.72
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.96
gMVP		0.96

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: rs1555421875; hg19: chr15-42691830;