6-98926940-T-A

Variant names:

• chr6-98926940-T-A
• rs754509338
• NM_001278716.2:c.49A>T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_001278716.2(FBXL4):​c.49A>T​(p.Ile17Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000547 in 1,461,858 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I17T) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: FBXL4 NM_001278716.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.97
• Publications: 1 publications found

Genes affected

FBXL4 (HGNC:13601): (F-box and leucine rich repeat protein 4) This gene encodes a member of the F-box protein family, which are characterized by an approximately 40 amino acid motif, the F-box. F-box proteins constitute one subunit of modular E3 ubiquitin ligase complexes, called SCF complexes, which function in phosphorylation-dependent ubiquitination. The F-box domain mediates protein-protein interactions and binds directly to S-phase kinase-associated protein 1. In addition to an F-box domain, the encoded protein contains at least 9 tandem leucine-rich repeats. The ubiquitin ligase complex containing the encoded protein may function in cell-cycle control by regulating levels of lysine-specific demethylase 4A. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2013]

FBXL4 Gene-Disease associations (from GenCC):

• Leigh syndrome

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• mitochondrial DNA depletion syndrome 13

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

• 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 1 curated benign missense variants. Gene score misZ: 0.55467 (below the threshold of 3.09). Trascript score misZ: 1.2845 (below the threshold of 3.09). GenCC associations: The gene is linked to Leigh syndrome, mitochondrial DNA depletion syndrome 13.
• BP4: Computational evidence support a benign effect (MetaRNN=0.11037263).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FBXL4	NM_001278716.2	c.49A>T	p.Ile17Leu	missense_variant	Exon 4 of 10	ENST00000369244.7	NP_001265645.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FBXL4	ENST00000369244.7	c.49A>T	p.Ile17Leu	missense_variant	Exon 4 of 10	1	NM_001278716.2	ENSP00000358247.1
FBXL4	ENST00000229971.2	c.49A>T	p.Ile17Leu	missense_variant	Exon 3 of 9	1		ENSP00000229971.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000119 AC: 3 AN: 251050 AF XY: 0.0000221

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000882

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461858 Hom.: 0 Cov.: 32 AF XY: 0.00000825 AC XY: 6 AN XY: 727230

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: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000348 AC: 3 AN: 86258

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: 0.00000360 AC: 4 AN: 1111988

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Mitochondrial DNA depletion syndrome 13 Uncertain:1

Aug 10, 2017

Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: reference population

The NM_012160.4:c.49A>T (NP_036292.2:p.Ile17Leu) [GRCH38: NC_000006.12:g.98926940T>A] variant in FBXL4 gene is interpretated to be a Uncertain Significance - Conflicting Evidence based on ACMG guidelines (PMID: 25741868). This variant meets one or more of the following evidence codes reported in the ACMG-guideline. PM2:This variant is absent in key population databases. BP4:Computational evidence/predictors indicate no impact on the FBXL4 structure, function, or protein-protein interaction. Based on this evidence code ClinGen Pathogenicity Calculator (PMID:28081714) suggested that the variant is Uncertain Significance - Conflicting Evidence. -

not provided Uncertain:1

Apr 04, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt FBXL4 protein function. ClinVar contains an entry for this variant (Variation ID: 437522). This variant has not been reported in the literature in individuals affected with FBXL4-related conditions. This variant is present in population databases (rs754509338, gnomAD 0.006%). This sequence change replaces isoleucine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 17 of the FBXL4 protein (p.Ile17Leu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.40	T
BayesDel_noAF	Benign	-0.63
CADD	Benign	17
DANN	Benign	0.96
DEOGEN2	Benign	0.047	T;T
Eigen	Benign	-0.21
Eigen_PC	Benign	-0.095
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Benign	0.68	.;T
M_CAP	Benign	0.0037	T
MetaRNN	Benign	0.11	T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.1	M;M
PhyloP100		4.0
PrimateAI	Uncertain	0.49	T
PROVEAN	Benign	0.070	N;N
REVEL	Benign	0.064
Sift	Benign	0.12	T;T
Sift4G	Benign	0.11	T;T
Polyphen		0.0	B;B
Vest4		0.20
MutPred		0.25		Gain of helix (P = 0.0199);Gain of helix (P = 0.0199);
MVP		0.31
MPC		0.064
ClinPred		0.38	T
GERP RS		1.6
Varity_R		0.13
gMVP		0.43
Mutation Taster		=85/15	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: rs754509338; hg19: chr6-99374816;