chr2-38071052-C-T

Variant names:

• chr2-38071052-C-T
• rs893198212
• NM_000104.4:c.1302G>A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000104.4(CYP1B1):​c.1302G>A​(p.Trp434*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,688 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CYP1B1 NM_000104.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.80

Genes affected

CYP1B1 (HGNC:2597): (cytochrome P450 family 1 subfamily B member 1) 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 enzyme encoded by this gene localizes to the endoplasmic reticulum and metabolizes procarcinogens such as polycyclic aromatic hydrocarbons and 17beta-estradiol. Mutations in this gene have been associated with primary congenital glaucoma; therefore it is thought that the enzyme also metabolizes a signaling molecule involved in eye development, possibly a steroid. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 54 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-38071052-C-T is Pathogenic according to our data. Variant chr2-38071052-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 456638.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr2-38071052-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CYP1B1	NM_000104.4	c.1302G>A	p.Trp434*	stop_gained	Exon 3 of 3	ENST00000610745.5	NP_000095.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CYP1B1	ENST00000610745.5	c.1302G>A	p.Trp434*	stop_gained	Exon 3 of 3	1	NM_000104.4	ENSP00000478561.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461688 Hom.: 0 Cov.: 50 AF XY: 0.00 AC XY: 0 AN XY: 727124

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital glaucoma Pathogenic:1

Apr 25, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

A different truncation downstream of this variant (p.Asp449Metfs*8) has been determined to be pathogenic (PMID: 9497261, 27820421, 14635112, 12036985). This suggests that deletion of this region of the CYP1B1 protein is causative of disease. This variant has been reported in an individual affected with primary congenital glaucoma (PMID: 16735994). This sequence change results in a premature translational stop signal in the last exon of the CYP1B1 mRNA at codon 434 (p.Trp434*). While this is not anticipated to result in nonsense mediated decay, it is expected to delete the last 110 amino acids (~20%) of the CYP1B1 protein. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	43
DANN	Uncertain	1.0
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Uncertain	0.90	D
Vest4		0.87
GERP RS		6.0

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: rs893198212; hg19: chr2-38298195;