rs769983049

chr1-171108154-T-Cchr1-171108154-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_001002294.3(FMO3):c.560T>C(p.Val187Ala) variant causes a missense change. 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 no classification for the single variant (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V187G) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: FMO3 NM_001002294.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.96

Genes affected

FMO3 (HGNC:3771): (flavin containing dimethylaniline monoxygenase 3) Flavin-containing monooxygenases (FMO) are an important class of drug-metabolizing enzymes that catalyze the NADPH-dependent oxygenation of various nitrogen-,sulfur-, and phosphorous-containing xenobiotics such as therapeutic drugs, dietary compounds, pesticides, and other foreign compounds. The human FMO gene family is composed of 5 genes and multiple pseudogenes. FMO members have distinct developmental- and tissue-specific expression patterns. The expression of this FMO3 gene, the major FMO expressed in adult liver, can vary up to 20-fold between individuals. This inter-individual variation in FMO3 expression levels is likely to have significant effects on the rate at which xenobiotics are metabolised and, therefore, is of considerable interest to the pharmaceutical industry. This transmembrane protein localizes to the endoplasmic reticulum of many tissues. Alternative splicing of this gene results in multiple transcript variants encoding different isoforms. Mutations in this gene cause the disorder trimethylaminuria (TMAu) which is characterized by the accumulation and excretion of unmetabolized trimethylamine and a distinctive body odor. In healthy individuals, trimethylamine is primarily converted to the non odorous trimethylamine N-oxide.[provided by RefSeq, Jan 2016]

(HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.979

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FMO3	NM_001002294.3	c.560T>C	p.Val187Ala	missense_variant	5/9	ENST00000367755.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FMO3	ENST00000367755.9	c.560T>C	p.Val187Ala	missense_variant	5/9	1	NM_001002294.3	P1
	ENST00000669750.1	n.533+59950A>G		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.64
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Uncertain	0.13
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Benign	0.10	T;T
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.94	D;D
M_CAP	Benign	0.054	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Uncertain	0.073	D
MutationAssessor	Pathogenic	3.5	M;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Benign	0.40	T
PROVEAN	Uncertain	-3.7	D;.
REVEL	Uncertain	0.53
Sift	Uncertain	0.014	D;.
Sift4G	Uncertain	0.051	T;D
Polyphen		1.0	D;.
Vest4		0.58
MutPred		0.93		Loss of stability (P = 0.0129);.;
MVP		0.44
MPC		0.25
ClinPred		0.99	D
GERP RS		5.1
Varity_R		0.44
gMVP		0.65

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: rs769983049; hg19: chr1-171077295;