6-98917373-C-A

Variant names:

• chr6-98917373-C-A
• rs1394080480
• NM_001278716.2:c.858+1G>T

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001278716.2(FBXL4):​c.858+1G>T variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000698 in 1,433,284 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
• Consequence: FBXL4 NM_001278716.2 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.54
• Publications: 2 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: Pathogenic. The variant received 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 3.4, offset of -25, new splice context is: tggGTattt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 6-98917373-C-A is Pathogenic according to our data. Variant chr6-98917373-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 437502.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FBXL4	NM_001278716.2	c.858+1G>T		splice_donor_variant, intron_variant	Intron 5 of 9	ENST00000369244.7	NP_001265645.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FBXL4	ENST00000369244.7	c.858+1G>T		splice_donor_variant, intron_variant	Intron 5 of 9	1	NM_001278716.2	ENSP00000358247.1
FBXL4	ENST00000229971.2	c.858+1G>T		splice_donor_variant, intron_variant	Intron 4 of 8	1		ENSP00000229971.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.98e-7 AC: 1 AN: 1433284 Hom.: 0 Cov.: 31 AF XY: 0.00000141 AC XY: 1 AN XY: 710306

African (AFR) AF: 0.00 AC: 0 AN: 32592

American (AMR) AF: 0.00 AC: 0 AN: 41250

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24152

East Asian (EAS) AF: 0.00 AC: 0 AN: 39424

South Asian (SAS) AF: 0.00 AC: 0 AN: 81244

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52344

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5558

European-Non Finnish (NFE) AF: 9.11e-7 AC: 1 AN: 1097568

Other (OTH) AF: 0.00 AC: 0 AN: 59152

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Mitochondrial DNA depletion syndrome 13 Pathogenic:1

Aug 10, 2017

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The NM_012160.4:c.858+1G>T (NP_036292.2:p.=) [GRCH38: NC_000006.12:g.98917373C>A] variant in FBXL4 gene is interpretated to be a Pathogenic based on ACMG guidelines (PMID: 25741868). This variant has been reported in PMID:27290639 . This variant meets one or more of the following evidence codes reported in the ACMG-guideline. PVS1:This variant is a predcted null variant in FBXL4 where loss of function is a known mechanism of disease. 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. 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 Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.37
CADD	Pathogenic	33
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.92
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		7.5
GERP RS		4.6
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.92		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.92		Position offset: 1

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

Other links and lift over

dbSNP: rs1394080480; hg19: chr6-99365249;