NM_020433.5:c.497T>G

Variant names:

• chr20-44160290-A-C
• rs876657835
• NM_020433.5:c.497T>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_020433.5(JPH2):​c.497T>G​(p.Leu166Arg) 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 (★). Synonymous variant affecting the same amino acid position (i.e. L166L) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: JPH2 NM_020433.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.68
• Publications: 0 publications found

Genes affected

JPH2 (HGNC:14202): (junctophilin 2) Junctional complexes between the plasma membrane and endoplasmic/sarcoplasmic reticulum are a common feature of all excitable cell types and mediate cross talk between cell surface and intracellular ion channels. The protein encoded by this gene is a component of junctional complexes and is composed of a C-terminal hydrophobic segment spanning the endoplasmic/sarcoplasmic reticulum membrane and a remaining cytoplasmic domain that shows specific affinity for the plasma membrane. This gene is a member of the junctophilin gene family. Alternative splicing has been observed at this locus and two variants encoding distinct isoforms are described. [provided by RefSeq, Jul 2008]

JPH2 Gene-Disease associations (from GenCC):

• hypertrophic cardiomyopathy 17

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae)
• cardiomyopathy, dilated, 2E

  Inheritance: Unknown, AR Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: MODERATE Submitted by: ClinGen
• dilated cardiomyopathy

  Inheritance: SD Classification: MODERATE Submitted by: ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_020433.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.914

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
JPH2	NM_020433.5	c.497T>G	p.Leu166Arg	missense_variant	Exon 2 of 6	ENST00000372980.4	NP_065166.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
JPH2	ENST00000372980.4	c.497T>G	p.Leu166Arg	missense_variant	Exon 2 of 6	5	NM_020433.5	ENSP00000362071.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Apr 09, 2015

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Leu166Arg variant in JPH2 has not been previously reported in individuals with cardiomyopathy. Data from large population studies is insufficient to asses s the frequency of this variant. Computational prediction tools and conservation analysis suggest that this variant may impact the protein, though this informat ion is not predictive enough to determine pathogenicity. In summary, the clinica l significance of the p.Leu166Arg variant is uncertain. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.17
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.69	D
Eigen	Uncertain	0.60
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.80	D
MetaRNN	Pathogenic	0.91	D
MetaSVM	Uncertain	-0.11	T
MutationAssessor	Uncertain	2.8	M
PhyloP100		8.7
PrimateAI	Pathogenic	0.96	D
PROVEAN	Pathogenic	-5.8	D
REVEL	Uncertain	0.62
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.91
MutPred		0.37		Loss of stability (P = 0.0148);
MVP		0.92
ClinPred		1.0	D
GERP RS		3.3
Varity_R		0.91
gMVP		0.89
Mutation Taster		=33/67	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: rs876657835; hg19: chr20-42788930;