rs201989042

chr6-98874354-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3 PP5

The NM_001278716.2(FBXL4):c.1790A>C(p.Gln597Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000329 in 1,613,216 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000035 (0 hom.)
• Consequence: FBXL4 NM_001278716.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3 U:1
• Conservation: PhyloP100: 7.67

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a repeat LRR 9 (size 25) in uniprot entity FBXL4_HUMAN there are 7 pathogenic changes around while only 0 benign (100%) in NM_001278716.2
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.831
• PP5: Variant 6-98874354-T-G is Pathogenic according to our data. Variant chr6-98874354-T-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 437486.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Pathogenic=1, Uncertain_significance=1}. Variant chr6-98874354-T-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FBXL4	NM_001278716.2	c.1790A>C	p.Gln597Pro	missense_variant	10/10	ENST00000369244.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FBXL4	ENST00000369244.7	c.1790A>C	p.Gln597Pro	missense_variant	10/10	1	NM_001278716.2	P1
FBXL4	ENST00000229971.2	c.1790A>C	p.Gln597Pro	missense_variant	9/9	1		P1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152170 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000200 AC: 5 AN: 250346 Hom.: 0 AF XY: 0.0000148 AC XY: 2 AN XY: 135306

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000442

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000349 AC: 51 AN: 1461046 Hom.: 0 Cov.: 31 AF XY: 0.0000344 AC XY: 25 AN XY: 726860

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000405

Gnomad4 OTH exome AF: 0.0000994

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152170 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74332

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000445 Hom.: 0

Bravo AF: 0.0000151

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Mitochondrial DNA depletion syndrome 13 Pathogenic:2

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.1790A>C (NP_036292.2:p.Gln597Pro) [GRCH38: NC_000006.12:g.98874354T>G] variant in FBXL4 gene is interpretated to be a Likely Pathogenic based on ACMG guidelines (PMID: 25741868). This variant has been reported in PMID:23993194 . 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. PP1:This variant is co-segregated with Mitochondrial DNA depletion syndrome 13 in multiple affected family members. 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. -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Sep 01, 2017	This mutation has been previously reported as disease-causing and was found once in our laboratory in trans with another pathogenic variant in an 8-year-old female with regression, basal ganglia abnormalities, absent speech, autistic features, hypotonia, spasticity, exercise intolerance, ataxia, severe renal tubular acidosis, scoliosis, primary mitochondrial respiratory chain disease -

not provided Pathogenic:1 Uncertain:1

Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	May 23, 2018	The Q597P variant has been published in patients who also harbored another variant in the FBXL4 gene with symptoms that include early-onset lactic acidemia, hypotonia, encephalopathy, hyperammonemia, defects in the respiratory chain and mitochondrial DNA depletion (Gai et al. 2013; Morton et al. 2016). The Q597P variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016). The Q597P variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. In summary, we interpret this variant as likely pathogenic; however, the possibility that it is benign cannot be excluded. -
Uncertain significance, no assertion criteria provided	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Mar 08, 2016	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.90
BayesDel_addAF	Uncertain	0.075	D
BayesDel_noAF	Uncertain	0.0
Cadd	Pathogenic	27
Dann	Uncertain	0.99
DEOGEN2	Benign	0.26	T;T
Eigen	Uncertain	0.67
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Benign	0.040	D
MetaRNN	Pathogenic	0.83	D;D
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.3	M;M
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.64	T
PROVEAN	Uncertain	-2.5	N;N
REVEL	Benign	0.24
Sift	Benign	0.14	T;T
Sift4G	Uncertain	0.027	D;D
Polyphen		0.99	D;D
Vest4		0.92
MutPred		0.58		Loss of catalytic residue at Q597 (P = 0.0297);Loss of catalytic residue at Q597 (P = 0.0297);
MVP		0.52
MPC		0.12
ClinPred		0.77	D
GERP RS		6.0
Varity_R		0.51
gMVP		0.87

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: rs201989042; hg19: chr6-99322230;