chr8-74320979-G-T

Variant names:

• chr8-74320979-G-T
• rs79761162
• NM_020647.4:c.309C>A

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_020647.4(JPH1):​c.309C>A​(p.Pro103Pro) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,458,728 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. P103P) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: JPH1 NM_020647.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.705
• Publications: 0 publications found

Genes affected

JPH1 (HGNC:14201): (junctophilin 1) 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. [provided by RefSeq, Jul 2008]

GDAP1 (HGNC:15968): (ganglioside induced differentiation associated protein 1) This gene encodes a member of the ganglioside-induced differentiation-associated protein family, which may play a role in a signal transduction pathway during neuronal development. Mutations in this gene have been associated with various forms of Charcot-Marie-Tooth Disease and neuropathy. Two transcript variants encoding different isoforms and a noncoding variant have been identified for this gene. [provided by RefSeq, Feb 2012]

GDAP1 Gene-Disease associations (from GenCC):

• Charcot-Marie-Tooth disease

  Inheritance: SD Classification: DEFINITIVE Submitted by: ClinGen
• Charcot-Marie-Tooth disease axonal type 2K

  Inheritance: AD, AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
• Charcot-Marie-Tooth disease recessive intermediate A

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
• autosomal dominant Charcot-Marie-Tooth disease type 2K

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Charcot-Marie-Tooth disease type 4A

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.51).
• BP7: Synonymous conserved (PhyloP=-0.705 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
JPH1	NM_020647.4	c.309C>A	p.Pro103Pro	synonymous_variant	Exon 1 of 6	ENST00000342232.5	NP_065698.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
JPH1	ENST00000342232.5	c.309C>A	p.Pro103Pro	synonymous_variant	Exon 1 of 6	1	NM_020647.4	ENSP00000344488.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1458728 Hom.: 0 Cov.: 32 AF XY: 0.00000276 AC XY: 2 AN XY: 725716

African (AFR) AF: 0.00 AC: 0 AN: 33242

American (AMR) AF: 0.00 AC: 0 AN: 44408

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25972

East Asian (EAS) AF: 0.00 AC: 0 AN: 39428

South Asian (SAS) AF: 0.00 AC: 0 AN: 85810

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53142

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5756

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1110696

Other (OTH) AF: 0.0000166 AC: 1 AN: 60274

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.51
CADD	Benign	11
DANN	Benign	0.94
PhyloP100		-0.70
PromoterAI		-0.028	Neutral

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs79761162; hg19: chr8-75233214;