chr2-53774239-C-T

Position:

• chr2-53774239-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001008708.4(CHAC2):​c.269C>T​(p.Thr90Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000684 in 1,461,826 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: CHAC2 NM_001008708.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.19

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_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.061184675).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CHAC2	NM_001008708.4	c.269C>T	p.Thr90Ile	missense_variant	3/3	ENST00000295304.5	NP_001008708.1
ASB3	NM_016115.5	c.-13-8654G>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.269C>T	p.Thr90Ile	missense_variant	3/3	1	NM_001008708.4	ENSP00000295304.4
ASB3	ENST00000263634.8	c.-13-8654G>A		intron_variant		1	NM_016115.5	ENSP00000263634.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461826 Hom.: 0 Cov.: 31 AF XY: 0.0000110 AC XY: 8 AN XY: 727214

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000809

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

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

Nov 26, 2024

The c.269C>T (p.T90I) alteration is located in exon 3 (coding exon 3) of the CHAC2 gene. This alteration results from a C to T substitution at nucleotide position 269, causing the threonine (T) at amino acid position 90 to be replaced by an isoleucine (I). 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	Benign	0.15
BayesDel_addAF	Benign	-0.30	T
BayesDel_noAF	Benign	-0.67
CADD	Benign	14
DANN	Benign	0.97
DEOGEN2	Benign	0.061	T
Eigen	Benign	-0.48
Eigen_PC	Benign	-0.31
FATHMM_MKL	Benign	0.72	D
LIST_S2	Benign	0.69	T
M_CAP	Benign	0.0051	T
MetaRNN	Benign	0.061	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.15	N
PrimateAI	Benign	0.42	T
PROVEAN	Benign	-1.4	N
REVEL	Benign	0.045
Sift	Benign	0.20	T
Sift4G	Benign	0.20	T
Polyphen		0.0	B
Vest4		0.050
MutPred		0.46		Loss of catalytic residue at T90 (P = 0.0214);
MVP		0.27
MPC		0.0023
ClinPred		0.14	T
GERP RS		1.2
Varity_R		0.090
gMVP		0.44

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: rs1674166009; hg19: chr2-54001376;