chr15-74720972-A-T

Position:

• chr15-74720972-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001319217.2(CYP1A1):​c.1248T>A​(p.His416Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CYP1A1 NM_001319217.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0720

Genes affected

CYP1A1 (HGNC:2595): (cytochrome P450 family 1 subfamily A member 1) This gene, CYP1A1, 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. This protein 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. The gene has been associated with lung cancer risk. A related family member, CYP1A2, is located approximately 25 kb away from CYP1A1 on chromosome 15. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Jan 2016]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.845

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CYP1A1	NM_001319217.2	c.1248T>A	p.His416Gln	missense_variant	6/7	ENST00000379727.8
CYP1A1	NM_000499.5	c.1248T>A	p.His416Gln	missense_variant	6/7
CYP1A1	NM_001319216.2	c.1167-198T>A		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CYP1A1	ENST00000379727.8	c.1248T>A	p.His416Gln	missense_variant	6/7	1	NM_001319217.2	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

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

Oct 25, 2022

The c.1248T>A (p.H416Q) alteration is located in exon 6 (coding exon 5) of the CYP1A1 gene. This alteration results from a T to A substitution at nucleotide position 1248, causing the histidine (H) at amino acid position 416 to be replaced by a glutamine (Q). 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	Uncertain	0.41
BayesDel_addAF	Uncertain	0.063	T
BayesDel_noAF	Benign	-0.15
CADD	Benign	19
DANN	Uncertain	0.99
DEOGEN2	Benign	0.081	T;D;D;D;.;T
Eigen	Uncertain	0.19
Eigen_PC	Benign	0.050
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Benign	0.77	T;T;.;.;D;D
M_CAP	Uncertain	0.10	D
MetaRNN	Pathogenic	0.85	D;D;D;D;D;D
MetaSVM	Uncertain	0.31	D
MutationAssessor	Pathogenic	3.0	.;M;M;M;.;.
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.58	T
PROVEAN	Pathogenic	-6.5	.;D;D;D;D;D
REVEL	Pathogenic	0.65
Sift	Uncertain	0.0040	.;D;D;D;D;D
Sift4G	Uncertain	0.021	D;D;D;D;D;D
Polyphen		1.0	.;D;D;D;.;.
Vest4		0.56
MutPred		0.61		.;Loss of catalytic residue at D417 (P = 0.062);Loss of catalytic residue at D417 (P = 0.062);Loss of catalytic residue at D417 (P = 0.062);.;.;
MVP		1.0
MPC		0.24
ClinPred		0.98	D
GERP RS		0.43
Varity_R		0.90
gMVP		0.81

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: rs1379156959; hg19: chr15-75013313;