chr4-186194522-G-C

Variant names:

• chr4-186194522-G-C
• rs199476185
• NM_207352.4:c.237G>C

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_207352.4(CYP4V2):​c.237G>C​(p.Glu79Asp) 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 1,461,804 control chromosomes in the GnomAD database, with no homozygous occurrence. 14/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CYP4V2 NM_207352.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -2.17
• 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

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_207352.4
• 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 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.

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.237G>C	p.Glu79Asp	missense	Exon 2 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.237G>C	p.Glu79Asp	missense	Exon 2 of 11	ENSP00000368079.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461804 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727202

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53408

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111954

Other (OTH) AF: 0.00 AC: 0 AN: 60392

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.037	T
BayesDel_noAF	Benign	-0.29
CADD	Benign	0.028
DANN	Benign	0.87
DEOGEN2	Benign	0.088	T
Eigen	Benign	-1.1
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.060	N
LIST_S2	Benign	0.035	T
M_CAP	Benign	0.029	D
MetaRNN	Uncertain	0.65	D
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.47	N
PhyloP100		-2.2
PrimateAI	Benign	0.31	T
PROVEAN	Benign	-0.55	N
REVEL	Uncertain	0.35
Sift	Benign	0.62	T
Sift4G	Benign	0.60	T
Polyphen		0.0010	B
Vest4		0.66
MutPred		0.75		Gain of glycosylation at Y84 (P = 0.0128)
MVP		0.61
MPC		0.062
ClinPred		0.027	T
GERP RS		-3.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.084
gMVP		0.43
Mutation Taster		=29/71	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: rs199476185; hg19: chr4-187115676;