chr20-44186542-G-A

Position:

• chr20-44186542-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_020433.5(JPH2):​c.164C>T​(p.Pro55Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,508 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 Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: JPH2 NM_020433.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.50

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.88

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
JPH2	NM_020433.5	c.164C>T	p.Pro55Leu	missense_variant	1/6	ENST00000372980.4	NP_065166.2
JPH2	NM_175913.4	c.164C>T	p.Pro55Leu	missense_variant	1/2		NP_787109.2
JPH2	XM_006723833.5	c.164C>T	p.Pro55Leu	missense_variant	1/2		XP_006723896.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
JPH2	ENST00000372980.4	c.164C>T	p.Pro55Leu	missense_variant	1/6	5	NM_020433.5	ENSP00000362071.3
JPH2	ENST00000342272.3	c.164C>T	p.Pro55Leu	missense_variant	1/2	1		ENSP00000344590.3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461508 Hom.: 0 Cov.: 65 AF XY: 0.00000275 AC XY: 2 AN XY: 727102

Gnomad4 AFR exome AF: 0.00

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: 0.00000630

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hypertrophic cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 21, 2016

This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a JPH2-related disease. In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies. This sequence change replaces proline with leucine at codon 55 of the JPH2 protein (p.Pro55Leu). The proline residue is highly conserved and there is a moderate physicochemical difference between proline and leucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.060
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.51	D;.
Eigen	Pathogenic	0.76
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Pathogenic	1.0	D;D
M_CAP	Pathogenic	0.43	D
MetaRNN	Pathogenic	0.88	D;D
MetaSVM	Uncertain	-0.19	T
MutationAssessor	Benign	1.9	M;M
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-8.8	D;D
REVEL	Uncertain	0.52
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;P
Vest4		0.74
MutPred		0.50		Loss of phosphorylation at Y52 (P = 0.1236);Loss of phosphorylation at Y52 (P = 0.1236);
MVP		0.91
ClinPred		1.0	D
GERP RS		4.6
Varity_R		0.87
gMVP		0.63

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: rs1060499996; hg19: chr20-42815182;