NM_000772.3:c.618G>T

Variant names:

• chr10-94695053-G-T
• rs779808698
• NM_000772.3:c.618G>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000772.3(CYP2C18):​c.618G>T​(p.Arg206Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,332 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: CYP2C18 NM_000772.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.43
• Publications: 0 publications found

Genes affected

CYP2C18 (HGNC:2620): (cytochrome P450 family 2 subfamily C member 18) 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. This protein localizes to the endoplasmic reticulum but its specific substrate has not yet been determined. The gene is located within a cluster of cytochrome P450 genes on chromosome 10q24. An additional gene, CYP2C17, was once thought to exist; however, CYP2C17 is now considered an artefact based on a chimera of CYP2C18 and CYP2C19. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

ENSG00000276490 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.09904164).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CYP2C18	NM_000772.3	c.618G>T	p.Arg206Ser	missense_variant	Exon 4 of 9	ENST00000285979.11	NP_000763.1
CYP2C18	NM_001128925.2	c.618G>T	p.Arg206Ser	missense_variant	Exon 4 of 8		NP_001122397.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CYP2C18	ENST00000285979.11	c.618G>T	p.Arg206Ser	missense_variant	Exon 4 of 9	1	NM_000772.3	ENSP00000285979.6
CYP2C18	ENST00000339022.6	c.618G>T	p.Arg206Ser	missense_variant	Exon 4 of 8	1		ENSP00000341293.5
ENSG00000276490	ENST00000464755.1	n.258G>T		non_coding_transcript_exon_variant	Exon 2 of 14	2		ENSP00000483243.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000800 AC: 2 AN: 250130 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000581

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1460332 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726446

African (AFR) AF: 0.00 AC: 0 AN: 33446

American (AMR) AF: 0.0000448 AC: 2 AN: 44646

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39584

South Asian (SAS) AF: 0.00 AC: 0 AN: 86078

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53380

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5068

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111710

Other (OTH) AF: 0.00 AC: 0 AN: 60292

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000301 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Feb 22, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.618G>T (p.R206S) alteration is located in exon 4 (coding exon 4) of the CYP2C18 gene. This alteration results from a G to T substitution at nucleotide position 618, causing the arginine (R) at amino acid position 206 to be replaced by a serine (S). 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	Benign	0.33
BayesDel_addAF	Benign	-0.34	T
BayesDel_noAF	Benign	-0.54
CADD	Benign	8.6
DANN	Benign	0.89
DEOGEN2	Benign	0.12	T;.
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.030	N
LIST_S2	Benign	0.035	T;T
M_CAP	Benign	0.023	T
MetaRNN	Benign	0.099	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.5	L;L
PhyloP100		-1.4
PROVEAN	Uncertain	-2.7	D;N
REVEL	Benign	0.023
Sift	Benign	0.29	T;T
Sift4G	Benign	0.44	T;T
Polyphen		0.078	B;.
Vest4		0.073
MutPred		0.35		Gain of disorder (P = 0.1112);Gain of disorder (P = 0.1112);
MVP		0.53
MPC		0.017
ClinPred		0.031	T
GERP RS		-1.7
Varity_R		0.23
gMVP		0.16
Mutation Taster		=99/1	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs779808698; hg19: chr10-96454810;