rs749863676

Positions:

• chr15-42392694-A-T

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM5 PP3_Strong PP5

The NM_000070.3(CAPN3):​c.1001A>T​(p.His334Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,613,886 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. H334Q) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CAPN3 NM_000070.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:7
• Conservation: PhyloP100: 9.11

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 9 ACMG points.

• PM1: In a active_site (size 0) in uniprot entity CAN3_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_000070.3
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.985
• PP5: Variant 15-42392694-A-T is Pathogenic according to our data. Variant chr15-42392694-A-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 285580.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=6, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CAPN3	NM_000070.3	c.1001A>T	p.His334Leu	missense_variant	7/24	ENST00000397163.8	NP_000061.1
CAPN3	NM_024344.2	c.1001A>T	p.His334Leu	missense_variant	7/23		NP_077320.1
CAPN3	NM_173087.2	c.857A>T	p.His286Leu	missense_variant	6/21		NP_775110.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CAPN3	ENST00000397163.8	c.1001A>T	p.His334Leu	missense_variant	7/24	1	NM_000070.3	ENSP00000380349	P2

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 152186 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000121

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251216 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135788

Gnomad AFR exome AF: 0.0000616

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS 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: 0.00000205 AC: 3 AN: 1461700 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727162

Gnomad4 AFR exome AF: 0.0000896

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000329 AC: 5 AN: 152186 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74334

Gnomad4 AFR AF: 0.000121

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000416

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:7

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1 Uncertain:4

Likely pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	May 01, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jun 15, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Athena Diagnostics	Oct 07, 2022	Available data are insufficient to determine the clinical significance of the variant at this time. The frequency of this variant in the general population is uninformative in assessment of its pathogenicity. (http://gnomad.broadinstitute.org) This variant is statistically more frequent than in the general population, which is weak evidence this variant may be disease causing. Computational tools predict that this variant is damaging. -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Jan 11, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jun 06, 2019	In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Not observed at a significant frequency in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 30564623, 18055493) -

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

Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Mar 20, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Mar 13, 2023	For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.His334 amino acid residue in CAPN3. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9150160). 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: 285580). This missense change has been observed in individual(s) with autosomal recessive CAPN3-related conditions (PMID: 18055493, 30564623; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is present in population databases (rs749863676, gnomAD 0.01%). This sequence change replaces histidine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 334 of the CAPN3 protein (p.His334Leu). -
Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Nov 08, 2022

Variant summary: CAPN3 c.1001A>T (p.His334Leu) results in a non-conservative amino acid change located in the Peptidase C2, calpain, catalytic domain (IPR001300) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251216 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1001A>T has been reported in the literature in individuals with a clinical suspicion for Limb-Girdle Muscular Dystrophy (example: Groen_2007 and Nallamilli_2018) and one classified the variant as VUS (Nallamilli_2018). These reports do not provide unequivocal conclusions about association of the variant with Limb-Girdle Muscular Dystrophy, Autosomal Recessive. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as VUS (n=6) and likely pathogenic (n=1). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	28
DANN	Benign	0.97
DEOGEN2	Uncertain	0.69	D;.;.;D
Eigen	Pathogenic	0.77
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.98	D;D;D;D
M_CAP	Pathogenic	0.73	D
MetaRNN	Pathogenic	0.98	D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.6	.;M;.;M
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.66	T
PROVEAN	Pathogenic	-11	.;D;D;D
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	.;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		0.97, 0.67, 0.97	.;D;P;D
Vest4		0.98
MVP		0.98
MPC		0.33
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.98
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: rs749863676; hg19: chr15-42684892;