rs3832024

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_001002294.3(FMO3):​c.591_592del​(p.Cys197Ter) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000744 in 1,613,886 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (β˜…β˜…). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000085 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000073 ( 0 hom. )

Consequence

FMO3
NM_001002294.3 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 2.11
Variant links:
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 1-171108182-CTG-C is Pathogenic according to our data. Variant chr1-171108182-CTG-C is described in ClinVar as [Pathogenic]. Clinvar id is 225364.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-171108182-CTG-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
FMO3NM_001002294.3 linkuse as main transcriptc.591_592del p.Cys197Ter frameshift_variant 5/9 ENST00000367755.9

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
FMO3ENST00000367755.9 linkuse as main transcriptc.591_592del p.Cys197Ter frameshift_variant 5/91 NM_001002294.3 P1
ENST00000669750.1 linkuse as main transcriptn.533+59920_533+59921del intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes
AF:
0.0000855
AC:
13
AN:
152080
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000656
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00212
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.000191
AC:
48
AN:
251246
Hom.:
0
AF XY:
0.000147
AC XY:
20
AN XY:
135796
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00250
Gnomad SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000732
AC:
107
AN:
1461688
Hom.:
0
AF XY:
0.0000674
AC XY:
49
AN XY:
727140
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00259
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
Gnomad4 OTH exome
AF:
0.0000662
GnomAD4 genome
AF:
0.0000854
AC:
13
AN:
152198
Hom.:
0
Cov.:
32
AF XY:
0.0000806
AC XY:
6
AN XY:
74404
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.0000655
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00213
Gnomad4 SAS
AF:
0.000208
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000712
Hom.:
0
Bravo
AF:
0.000189

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingClinical Genetics Laboratory, Skane University Hospital LundAug 28, 2023- -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 24, 2024This sequence change creates a premature translational stop signal (p.Cys197*) in the FMO3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in FMO3 are known to be pathogenic (PMID: 20301282). This variant is present in population databases (rs780358952, gnomAD 0.2%). This premature translational stop signal has been observed in individual(s) with trimethylaminuria (PMID: 16996766, 17584019, 31401033, 33831674). This variant is also known as 21243_21244TG deletion. ClinVar contains an entry for this variant (Variation ID: 225364). For these reasons, this variant has been classified as Pathogenic. -
Trimethylaminuria Pathogenic:1
Pathogenic, criteria provided, single submitterreference populationSoonchunhyang University Bucheon Hospital, Soonchunhyang University Medical CenterMar 18, 2016- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs3832024; hg19: chr1-171077323; API