1-171116245-T-C

Variant summary

Our verdict is Benign. Variant got -17 ACMG points: 0P and 17B. BP4_Strong BP6_Very_Strong BP7 BS2

The NM_001002294.3(FMO3):c.1221T>C(p.Asn407=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000687 in 1,605,010 control chromosomes in the GnomAD database, including 7 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0036 (3 hom., cov: 32)
  • Exomes 𝑓: 0.00038 (4 hom.)
• Consequence: FMO3 NM_001002294.3 synonymous
• Clinical Significance: Benign criteria provided, multiple submitters, no conflicts B:3
• Conservation: PhyloP100: 0.331

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 Benign. Variant got -17 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.52).
• BP6: Variant 1-171116245-T-C is Benign according to our data. Variant chr1-171116245-T-C is described in ClinVar as [Benign]. Clinvar id is 260066.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=0.331 with no splicing effect.
• BS2: High Homozygotes in GnomAd at 3 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FMO3	NM_001002294.3	c.1221T>C	p.Asn407=	synonymous_variant	8/9	ENST00000367755.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FMO3	ENST00000367755.9	c.1221T>C	p.Asn407=	synonymous_variant	8/9	1	NM_001002294.3	P1
	ENST00000669750.1	n.533+51859A>G		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes AF: 0.00357 AC: 544 AN: 152170 Hom.: 3 Cov.: 32

Gnomad AFR AF: 0.0123

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00164

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000588

Gnomad OTH AF: 0.00336

GnomAD3 exomes AF: 0.00101 AC: 252 AN: 250558 Hom.: 2 AF XY: 0.000739 AC XY: 100 AN XY: 135398

Gnomad AFR exome AF: 0.0139

Gnomad AMR exome AF: 0.000696

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000328

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000177

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000383 AC: 556 AN: 1452722 Hom.: 4 Cov.: 27 AF XY: 0.000347 AC XY: 251 AN XY: 723420

Gnomad4 AFR exome AF: 0.0136

Gnomad4 AMR exome AF: 0.000649

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000465

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000136

Gnomad4 OTH exome AF: 0.000782

GnomAD4 genome AF: 0.00359 AC: 546 AN: 152288 Hom.: 3 Cov.: 32 AF XY: 0.00345 AC XY: 257 AN XY: 74474

Gnomad4 AFR AF: 0.0123

Gnomad4 AMR AF: 0.00164

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000588

Gnomad4 OTH AF: 0.00332

Alfa AF: 0.000825 Hom.: 3

Bravo AF: 0.00433

Asia WGS AF: 0.000578 AC: 2 AN: 3476

ClinVar

Significance: Benign

Submissions summary: Benign:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:1

Benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

-

- -

not provided Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Jan 26, 2024

- -

Trimethylaminuria Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.52
Cadd	Benign	3.8
Dann	Benign	0.62

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: rs79553697; hg19: chr1-171085385;