15-74750139-C-T

Variant names:

• chr15-74750139-C-T
• NM_000761.5:c.401C>T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_000761.5(CYP1A2):​c.401C>T​(p.Ala134Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,756 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 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: 6.8e-7 (0 hom.)
• Consequence: CYP1A2 NM_000761.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.27

Genes affected

CYP1A2 (HGNC:2596): (cytochrome P450 family 1 subfamily A member 2) This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. The protein encoded by this gene localizes to the endoplasmic reticulum and its expression is induced by some polycyclic aromatic hydrocarbons (PAHs), some of which are found in cigarette smoke. The enzyme's endogenous substrate is unknown; however, it is able to metabolize some PAHs to carcinogenic intermediates. Other xenobiotic substrates for this enzyme include caffeine, aflatoxin B1, and acetaminophen. The transcript from this gene contains four Alu sequences flanked by direct repeats in the 3' untranslated region. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.2814942).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CYP1A2	NM_000761.5	c.401C>T	p.Ala134Val	missense_variant	Exon 2 of 7	ENST00000343932.5	NP_000752.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CYP1A2	ENST00000343932.5	c.401C>T	p.Ala134Val	missense_variant	Exon 2 of 7	1	NM_000761.5	ENSP00000342007.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461756 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727182

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: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Apr 18, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.401C>T (p.A134V) alteration is located in exon 2 (coding exon 1) of the CYP1A2 gene. This alteration results from a C to T substitution at nucleotide position 401, causing the alanine (A) at amino acid position 134 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	Benign	0.13
BayesDel_addAF	Benign	-0.097	T
BayesDel_noAF	Benign	-0.38
CADD	Benign	20
DANN	Uncertain	1.0
DEOGEN2	Benign	0.39	T
Eigen	Uncertain	0.33
Eigen_PC	Uncertain	0.38
FATHMM_MKL	Uncertain	0.87	D
LIST_S2	Uncertain	0.89	D
M_CAP	Benign	0.015	T
MetaRNN	Benign	0.28	T
MetaSVM	Benign	-0.49	T
MutationAssessor	Benign	1.9	L
PrimateAI	Benign	0.47	T
PROVEAN	Benign	-1.8	N
REVEL	Benign	0.20
Sift	Benign	0.070	T
Sift4G	Benign	0.17	T
Vest4		0.085
MutPred		0.54		Loss of disorder (P = 0.1053);
MVP		0.60
MPC		0.098
ClinPred		0.73	D
GERP RS		4.8
Varity_R		0.22
gMVP		0.60

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: chr15-75042480; COSMIC: COSV100673914;