6-98899281-C-A

Position:

• chr6-98899281-C-A

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Moderate PP5_Moderate

The NM_001278716.2(FBXL4):​c.1304G>T​(p.Arg435Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,424 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R435Q) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: FBXL4 NM_001278716.2 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.57

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]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM1: In a repeat LRR 3 (size 21) in uniprot entity FBXL4_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_001278716.2
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr6-98899281-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 430470.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Pathogenic=1, Uncertain_significance=1}.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.906
• PP5: Variant 6-98899281-C-A is Pathogenic according to our data. Variant chr6-98899281-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 437476.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr6-98899281-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FBXL4	NM_001278716.2	c.1304G>T	p.Arg435Leu	missense_variant	7/10	ENST00000369244.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FBXL4	ENST00000369244.7	c.1304G>T	p.Arg435Leu	missense_variant	7/10	1	NM_001278716.2	P1
FBXL4	ENST00000229971.2	c.1304G>T	p.Arg435Leu	missense_variant	6/9	1		P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461424 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727006

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Mitochondrial DNA depletion syndrome 13 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

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

Aug 10, 2017

The NM_012160.4:c.1304G>T (NP_036292.2:p.Arg435Leu) [GRCH38: NC_000006.12:g.98899281C>A] variant in FBXL4 gene is interpretated to be a Likely Pathogenic based on ACMG guidelines (PMID: 25741868). This variant has been reported in PMID:25868664 . 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. PM3:Detected in trans with a pathogenic variant for Mitochondrial DNA depletion syndrome 13 which is a recessive disorder. PP2:This is a missense variant in FBXL4 with a low rate of benign and high rate of pathogenic missense variations. PP3:Computational evidence/predictors indicate the variant has deleterious effect on FBXL4 structure, function, or protein-protein interaction. PP4:Patient’s phenotype or family history is highly specific for FBXL4. PP5:Reputable source(s) suggest that the variant is pathogenic. Based on this evidence code ClinGen Pathogenicity Calculator (PMID:28081714) suggested that the variant is Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Benign	0.29	T;T
Eigen	Pathogenic	0.70
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	.;D
M_CAP	Uncertain	0.10	D
MetaRNN	Pathogenic	0.91	D;D
MetaSVM	Benign	-1.0	T
MutationAssessor	Uncertain	2.8	M;M
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.64	T
PROVEAN	Pathogenic	-5.3	D;D
REVEL	Uncertain	0.56
Sift	Uncertain	0.0020	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		0.99	D;D
Vest4		0.93
MutPred		0.76		Gain of sheet (P = 0.0477);Gain of sheet (P = 0.0477);
MVP		0.54
MPC		0.43
ClinPred		1.0	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.68
gMVP		0.81

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.21		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.21		Position offset: -13

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs754142863; hg19: chr6-99347157;