chr1-228149857-A-G

Variant names:

• chr1-228149857-A-G
• rs587777496
• NM_020435.4:c.-170A>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 3P and 1B. PM2 PP5 BP4

The NM_020435.4(GJC2):​c.-170A>G variant causes a upstream gene change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: GJC2 NM_020435.4 upstream_gene
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1 O:1
• Conservation: PhyloP100: 3.09
• Publications: 3 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, Orphanet, Labcorp Genetics (formerly Invitae)
• 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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-228149857-A-G is Pathogenic according to our data. Variant chr1-228149857-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 139577.
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.41). . Strength limited to SUPPORTING due to the PP5.

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.-170A>G		upstream_gene	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.-170A>G		upstream_gene	N/A	ENSP00000355675.2	Q5T442

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 228 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 172

African (AFR) AF: 0.00 AC: 0 AN: 4

American (AMR) AF: 0.00 AC: 0 AN: 2

Ashkenazi Jewish (ASJ) AC: 0 AN: 0

East Asian (EAS) AF: 0.00 AC: 0 AN: 2

South Asian (SAS) AF: 0.00 AC: 0 AN: 16

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 2

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 196

Other (OTH) AF: 0.00 AC: 0 AN: 2

GnomAD4 genome Cov.: 34

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000151

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
2	-	-	Hypomyelinating leukodystrophy 2 (3)
-	1	-	Spastic paraplegia (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.41
CADD	Benign	20
DANN	Benign	0.91
PhyloP100		3.1
PromoterAI		-0.056	Neutral
Mutation Taster		=111/189	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs587777496; hg19: chr1-228337558;