4-186208943-G-C

Variant names:

• chr4-186208943-G-C
• rs199476201
• NM_207352.4:c.1169G>C

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP2 PP3_Strong

The NM_207352.4(CYP4V2):​c.1169G>C​(p.Arg390Pro) variant causes a missense change involving the alteration of a 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R390C) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: CYP4V2 NM_207352.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.82
• Publications: 0 publications found

Genes affected

CYP4V2 (HGNC:23198): (cytochrome P450 family 4 subfamily V member 2) This gene encodes a member of the cytochrome P450 hemethiolate protein superfamily which are involved in oxidizing various substrates in the metabolic pathway. It is implicated in the metabolism of fatty acid precursors into n-3 polyunsaturated fatty acids. Mutations in this gene result in Bietti crystalline corneoretinal dystrophy. [provided by RefSeq, Jul 2008]

CYP4V2 Gene-Disease associations (from GenCC):

• Bietti crystalline corneoretinal dystrophy

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Illumina, Orphanet, Labcorp Genetics (formerly Invitae), G2P, ClinGen

ENSG00000290316 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 11 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, 5 uncertain in NM_207352.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr4-186208942-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 1075096.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 24 curated pathogenic missense variants (we use a threshold of 10). The gene has 7 curated benign missense variants. Gene score misZ: -0.12103 (below the threshold of 3.09). Trascript score misZ: -0.14191 (below the threshold of 3.09). GenCC associations: The gene is linked to Bietti crystalline corneoretinal dystrophy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_207352.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CYP4V2	NM_207352.4	MANE Select	c.1169G>C	p.Arg390Pro	missense	Exon 9 of 11	NP_997235.3

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CYP4V2	ENST00000378802.5	TSL:1 MANE Select	c.1169G>C	p.Arg390Pro	missense	Exon 9 of 11	ENSP00000368079.4
	CYP4V2	ENST00000502665.1	TSL:1	n.404G>C		non_coding_transcript_exon	Exon 3 of 5
	CYP4V2	ENST00000507209.5	TSL:1	n.5867G>C		non_coding_transcript_exon	Exon 4 of 6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 39

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Apr 10, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 390 of the CYP4V2 protein (p.Arg390Pro). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with CYP4V2-related conditions. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CYP4V2 protein function with a positive predictive value of 80%. This variant disrupts the p.Arg390 amino acid residue in CYP4V2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 21565171, 33090715). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.54	D
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Pathogenic	0.34	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.8	H
PhyloP100		9.8
PrimateAI	Uncertain	0.63	T
PROVEAN	Pathogenic	-6.7	D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.92		Gain of glycosylation at T388 (P = 0.0642)
MVP		1.0
MPC		0.48
ClinPred		1.0	D
GERP RS		5.7
PromoterAI		-0.014	Neutral
Varity_R		0.99
gMVP		0.99
Mutation Taster		=4/96	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.10		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: rs199476201; hg19: chr4-187130097;