1-228157790-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_020435.4(GJC2):c.32G>C(p.Arg11Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000784 in 1,274,822 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R11Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 7.8e-7 (0 hom.)
• Consequence: GJC2 NM_020435.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.66

Genes affected

GJC2 (HGNC:17494): (gap junction protein gamma 2) This gene encodes a gap junction protein. Gap junction proteins are members of a large family of homologous connexins and comprise 4 transmembrane, 2 extracellular, and 3 cytoplasmic domains. This gene plays a key role in central myelination and is involved in peripheral myelination in humans. Defects in this gene are the cause of autosomal recessive Pelizaeus-Merzbacher-like disease-1. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.96

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GJC2	NM_020435.4	c.32G>C	p.Arg11Pro	missense_variant	2/2	ENST00000366714.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GJC2	ENST00000366714.3	c.32G>C	p.Arg11Pro	missense_variant	2/2	1	NM_020435.4	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 7.84e-7 AC: 1 AN: 1274822 Hom.: 0 Cov.: 38 AF XY: 0.00 AC XY: 0 AN XY: 625678

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: 0.00000101

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

Lymphatic malformation 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Neuberg Centre For Genomic Medicine, NCGM

Mar 01, 2023

The missense variant c.32G>C (p.Arg11Pro) in the GJC2 gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. This variant is novel (not in any individuals) in gnomAD Exomes and 1000 Genomes. The amino acid Arginine at position 11 is changed to a Proline changing protein sequence and it might alter its composition and physico-chemical properties. The variant is predicted as damaging by SIFT. The amino acid change p.Arg11Pro in GJC2 is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.52
Cadd	Pathogenic	32
Dann	Uncertain	0.99
DEOGEN2	Pathogenic	0.90	D
Eigen	Uncertain	0.66
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.95	D
M_CAP	Pathogenic	0.95	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.9	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-5.9	D
REVEL	Pathogenic	0.86
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.85
MutPred		0.67		Gain of catalytic residue at R11 (P = 0.0648);
MVP		0.96
ClinPred		1.0	D
GERP RS		4.2
Varity_R		0.96
gMVP		0.99

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-228345491;