rs1555853257

Positions:

• chr20-44115709-T-TCCGCGCCTTCTTCTTGGC

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PM4

The NM_020433.5(JPH2):​c.1965_1966insGCCAAGAAGAAGGCGCGG​(p.Ala650_Arg655dup) variant causes a inframe insertion change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: JPH2 NM_020433.5 inframe_insertion
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0600

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
• PM4: Nonframeshift variant in NON repetitive region in NM_020433.5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
JPH2	NM_020433.5	c.1965_1966insGCCAAGAAGAAGGCGCGG	p.Ala650_Arg655dup	inframe_insertion	4/6	ENST00000372980.4	NP_065166.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
JPH2	ENST00000372980.4	c.1965_1966insGCCAAGAAGAAGGCGCGG	p.Ala650_Arg655dup	inframe_insertion	4/6	5	NM_020433.5	ENSP00000362071	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

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

Oct 03, 2016

This sequence change inserts 18 nucleotides in exon 4 of the JPH2 mRNA (c.1948_1965dup18). This leads to the insertion of 6 amino acid residues in the JPH2 protein (p.Ala650_Arg655dup) but otherwise preserves the integrity of the reading frame. 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 in-frame duplication with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. Experimental studies and prediction algorithms are not available for this variant, and the functional significance of the duplicated amino acids is currently unknown. -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1555853257; hg19: chr20-42744349;