chr2-53774386-G-T

Position:

• chr2-53774386-G-T

Variant summary

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

The NM_001008708.4(CHAC2):​c.416G>T​(p.Gly139Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,613,380 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000034 (1 hom.)
• Consequence: CHAC2 NM_001008708.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.94

Genes affected

CHAC2 (HGNC:32363): (ChaC glutathione specific gamma-glutamylcyclotransferase 2) The protein encoded by this gene is a gamma-glutamyl cyclotransferase that catalyzes the conversion of glutathione to 5-oxoproline and cysteinylglycine. It is thought that this gene is upregulated in response to endoplasmic reticulum stress and that the glutathione depletion enhances apoptosis. [provided by RefSeq, Sep 2016]

ASB3 (HGNC:16013): (ankyrin repeat and SOCS box containing 3) The protein encoded by this gene is a member of the ankyrin repeat and SOCS box-containing (ASB) family of proteins. They contain ankyrin repeat sequence and SOCS box domain. The SOCS box serves to couple suppressor of cytokine signalling (SOCS) proteins and their binding partners with the elongin B and C complex, possibly targeting them for degradation. Alternatively spliced transcript variants have been described for this gene. [provided by RefSeq, Jan 2011]

GPR75-ASB3 (HGNC:40043): (GPR75-ASB3 readthrough) This locus represents naturally occurring read-through transcription between the neighboring GPR75 (G protein-coupled receptor 75) and ASB3 (ankyrin repeat and SOCS box containing 3) on chromosome 2. The transcript includes exons from both GPR75 and ASB3 and translation initiates in the 5' non-coding exon of GPR75. The resulting protein has a novel N-terminus but is otherwise identical to that encoded by ASB3.[provided by RefSeq, Feb 2011]

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, 0.98

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHAC2	NM_001008708.4	c.416G>T	p.Gly139Val	missense_variant	3/3	ENST00000295304.5	NP_001008708.1
ASB3	NM_016115.5	c.-13-8801C>A		intron_variant		ENST00000263634.8	NP_057199.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CHAC2	ENST00000295304.5	c.416G>T	p.Gly139Val	missense_variant	3/3	1	NM_001008708.4	ENSP00000295304.4
ASB3	ENST00000263634.8	c.-13-8801C>A		intron_variant		1	NM_016115.5	ENSP00000263634.2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152178 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461202 Hom.: 1 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 726828

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: 0.00

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152178 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74344

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 10, 2024

The c.416G>T (p.G139V) alteration is located in exon 3 (coding exon 3) of the CHAC2 gene. This alteration results from a G to T substitution at nucleotide position 416, causing the glycine (G) at amino acid position 139 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.46	T
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Uncertain	0.18	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	0.82	D
MutationAssessor	Pathogenic	4.3	H
PrimateAI	Uncertain	0.65	T
PROVEAN	Pathogenic	-8.9	D
REVEL	Pathogenic	0.89
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.86		Loss of relative solvent accessibility (P = 0.0186);
MVP		0.87
MPC		0.0066
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.99
gMVP		0.92

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

LitVar

Other links and lift over

dbSNP: rs767990230; hg19: chr2-54001523;