1-228158951-CC-TA

Variant names:

• chr1-228158951-CC-TA
• NM_020435.4:c.1193_1194delCCinsTA
• GJC2 p.Thr398Ile

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP2

The NM_020435.4(GJC2):​c.1193_1194delCCinsTA​(p.Thr398Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Benign in ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GJC2 NM_020435.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.83
• Publications: 0 publications found

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]

GJC2 Gene-Disease associations (from GenCC):

• hypomyelinating leukodystrophy 2

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, G2P, ClinGen, Labcorp Genetics (formerly Invitae), Orphanet
• lymphatic malformation 3

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• hereditary spastic paraplegia 44

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
• lymphatic malformation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 19 curated pathogenic missense variants (we use a threshold of 10). The gene has 3 curated benign missense variants. Gene score misZ: 1.8719 (below the threshold of 3.09). Trascript score misZ: -1.3976 (below the threshold of 3.09). GenCC associations: The gene is linked to hypomyelinating leukodystrophy 2, hereditary spastic paraplegia 44, lymphatic malformation, lymphatic malformation 3.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020435.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GJC2	NM_020435.4	MANE Select	c.1193_1194delCCinsTA	p.Thr398Ile	missense	N/A	NP_065168.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GJC2	ENST00000366714.3	TSL:1 MANE Select	c.1193_1194delCCinsTA	p.Thr398Ile	missense	N/A	ENSP00000355675.2	Q5T442
	GJC2	ENST00000886860.1		c.1193_1194delCCinsTA	p.Thr398Ile	missense	N/A	ENSP00000556919.1
	GJC2	ENST00000963922.1		c.1193_1194delCCinsTA	p.Thr398Ile	missense	N/A	ENSP00000633981.1

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.8

Splicing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr1-228346652;