6-98880593-C-G

Variant names:

• chr6-98880593-C-G
• rs745312139
• NM_001278716.2:c.1349G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PM5 PP2 PP3

The NM_001278716.2(FBXL4):​c.1349G>C​(p.Cys450Ser) variant causes a missense change involving the alteration of a conserved nucleotide. 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C450W) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: FBXL4 NM_001278716.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.38
• Publications: 0 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: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr6-98880592-A-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1696842.Status of the report is criteria_provided_single_submitter, 1 stars.
• 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.797

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FBXL4	NM_001278716.2	c.1349G>C	p.Cys450Ser	missense_variant	Exon 8 of 10	ENST00000369244.7	NP_001265645.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FBXL4	ENST00000369244.7	c.1349G>C	p.Cys450Ser	missense_variant	Exon 8 of 10	1	NM_001278716.2	ENSP00000358247.1
FBXL4	ENST00000229971.2	c.1349G>C	p.Cys450Ser	missense_variant	Exon 7 of 9	1		ENSP00000229971.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Nov 24, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1349G>C (p.C450S) alteration is located in exon 7 (coding exon 5) of the FBXL4 gene. This alteration results from a G to C substitution at nucleotide position 1349, causing the cysteine (C) at amino acid position 450 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1

Jan 14, 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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. This variant has not been reported in the literature in individuals affected with FBXL4-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces cysteine, which is neutral and slightly polar, with serine, which is neutral and polar, at codon 450 of the FBXL4 protein (p.Cys450Ser). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.45
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.050
CADD	Benign	23
DANN	Benign	0.83
DEOGEN2	Benign	0.046	T;T
Eigen	Uncertain	0.34
Eigen_PC	Uncertain	0.47
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Benign	0.85	.;D
M_CAP	Benign	0.017	T
MetaRNN	Pathogenic	0.80	D;D
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.4	M;M
PhyloP100		7.4
PrimateAI	Uncertain	0.72	T
PROVEAN	Benign	-0.34	N;N
REVEL	Uncertain	0.34
Sift	Benign	0.61	T;T
Sift4G	Benign	0.81	T;T
Polyphen		0.25	B;B
Vest4		0.83
MutPred		0.76		Gain of disorder (P = 0.0042);Gain of disorder (P = 0.0042);
MVP		0.46
MPC		0.12
ClinPred		0.68	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.29
gMVP		0.78
Mutation Taster		=60/40	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.14		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: rs745312139; hg19: chr6-99328469;