rs1555420621

Positions:

• chr15-42388947-G-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.652G>C​(p.Ala218Pro) 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. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CAPN3 NM_000070.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts 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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 12 uncertain in NM_000070.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.966

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CAPN3	NM_000070.3	c.652G>C	p.Ala218Pro	missense_variant	5/24	ENST00000397163.8
CAPN3	NM_024344.2	c.652G>C	p.Ala218Pro	missense_variant	5/23
CAPN3	NM_173087.2	c.652G>C	p.Ala218Pro	missense_variant	5/21

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CAPN3	ENST00000397163.8	c.652G>C	p.Ala218Pro	missense_variant	5/24	1	NM_000070.3	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Feb 06, 2017

- -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 12, 2022

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 446983). 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 alanine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 218 of the CAPN3 protein (p.Ala218Pro). -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Revvity Omics, Revvity

Dec 28, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.60	D;.;.;D
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D;D;D;D
M_CAP	Uncertain	0.28	D
MetaRNN	Pathogenic	0.97	D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.5	.;H;H;H
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Pathogenic	0.85	D
PROVEAN	Pathogenic	-4.7	D;D;D;D
REVEL	Pathogenic	0.91
Sift	Uncertain	0.0010	D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D
Polyphen		1.0, 1.0	.;D;D;D
Vest4		0.90
MutPred		0.86		Gain of disorder (P = 0.0896);Gain of disorder (P = 0.0896);Gain of disorder (P = 0.0896);Gain of disorder (P = 0.0896);
MVP		0.99
MPC		0.72
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.99
gMVP		0.94

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs1555420621; hg19: chr15-42681145;