chr2-38075218-C-G

Variant names:

• chr2-38075218-C-G
• rs72549387
• NM_000104.4:c.171G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM2 PP2 PP3_Moderate

The NM_000104.4(CYP1B1):​c.171G>C​(p.Trp57Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,254 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 Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 34)
• Consequence: CYP1B1 NM_000104.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.28
• Publications: 33 publications found

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]

CYP1B1-AS1 (HGNC:28543): (CYP1B1 antisense RNA 1)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_000104.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 35 curated pathogenic missense variants (we use a threshold of 10). The gene has 9 curated benign missense variants. Trascript score misZ: -2.0997 (below the threshold of 3.09). GenCC associations: The gene is linked to Peters anomaly, anterior segment dysgenesis 6, glaucoma 3A, CYP1B1-related glaucoma with or without anterior segment dysgenesis, congenital glaucoma.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.874

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CYP1B1	NM_000104.4	c.171G>C	p.Trp57Cys	missense_variant	Exon 2 of 3	ENST00000610745.5	NP_000095.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CYP1B1	ENST00000610745.5	c.171G>C	p.Trp57Cys	missense_variant	Exon 2 of 3	1	NM_000104.4	ENSP00000478561.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152254 Hom.: 0 Cov.: 34

Gnomad AFR AF: 0.0000241

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 36

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152254 Hom.: 0 Cov.: 34 AF XY: 0.0000134 AC XY: 1 AN XY: 74386

African (AFR) AF: 0.0000241 AC: 1 AN: 41474

American (AMR) AF: 0.00 AC: 0 AN: 15290

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5188

South Asian (SAS) AF: 0.00 AC: 0 AN: 4836

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10630

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68044

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Apr 22, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: CYP1B1 c.171G>C (p.Trp57Cys) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 201850 control chromosomes. c.171G>C has been reported in the literature in at-least two siblings affected with Primary Congenital Glaucoma (Stoilov_1998), and at a heterozygous status in unspecified individual(s) with open-angle glaucoma (Achary_2006). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 16688110, 9497261). No submitters have cited clinical-significance assessments for this variant to ClinVar. Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.67
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	29
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.61	D;D;.
Eigen	Uncertain	0.63
Eigen_PC	Uncertain	0.46
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Pathogenic	0.98	.;D;D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.87	D;D;D
MetaSVM	Uncertain	0.37	D
MutationAssessor	Pathogenic	3.5	H;H;.
PhyloP100		3.3
PrimateAI	Pathogenic	0.83	D
Sift4G	Pathogenic	0.0010	D;D;.
Vest4		0.68
MVP		0.41
ClinPred		0.98	D
GERP RS		4.2
Varity_R		0.96
gMVP		0.92
Mutation Taster		=2/98	disease causing

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

Other links and lift over

dbSNP: rs72549387; hg19: chr2-38302361;