chr20-44159918-G-C

Position:

• chr20-44159918-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_020433.5(JPH2):​c.869C>G​(p.Thr290Ser) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,459,688 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: JPH2 NM_020433.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.02

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.20538253).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
JPH2	NM_020433.5	c.869C>G	p.Thr290Ser	missense_variant	2/6	ENST00000372980.4	NP_065166.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
JPH2	ENST00000372980.4	c.869C>G	p.Thr290Ser	missense_variant	2/6	5	NM_020433.5	ENSP00000362071	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459688 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 726052

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: 9.00e-7

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

Mar 17, 2020

This variant has not been reported in the literature in individuals with JPH2-related conditions. 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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant is not present in population databases (ExAC no frequency). This sequence change replaces threonine with serine at codon 290 of the JPH2 protein (p.Thr290Ser). The threonine residue is moderately conserved and there is a small physicochemical difference between threonine and serine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Benign	-0.32	T
BayesDel_noAF	Benign	-0.69
CADD	Benign	19
DANN	Benign	0.88
DEOGEN2	Benign	0.38	T
Eigen	Benign	-0.46
Eigen_PC	Benign	-0.39
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Benign	0.73	T
M_CAP	Benign	0.046	D
MetaRNN	Benign	0.21	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.68	N
MutationTaster	Benign	1.0	N
PrimateAI	Pathogenic	0.85	D
PROVEAN	Benign	-2.1	N
REVEL	Benign	0.086
Sift	Benign	0.16	T
Sift4G	Benign	0.34	T
Polyphen		0.0	B
Vest4		0.14
MutPred		0.25		Loss of sheet (P = 0.0817);
MVP		0.63
ClinPred		0.15	T
GERP RS		2.0
Varity_R		0.11
gMVP		0.30

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: rs757257639; hg19: chr20-42788558; COSMIC: COSV65902225;