6-98917570-T-A

Variant names:

• chr6-98917570-T-A
• rs1554221189
• NM_001278716.2:c.662A>T

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM2 PM5 PP2 PP3_Moderate PP5_Moderate

The NM_001278716.2(FBXL4):​c.662A>T​(p.Asp221Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000684 in 1,461,700 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. D221H) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: FBXL4 NM_001278716.2 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.65
• 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: Likely_pathogenic. The variant received 9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr6-98917571-C-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 437472.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, 0.883
• PP5: Variant 6-98917570-T-A is Pathogenic according to our data. Variant chr6-98917570-T-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 437473.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001278716.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FBXL4	NM_001278716.2	MANE Select	c.662A>T	p.Asp221Val	missense	Exon 5 of 10	NP_001265645.1
	FBXL4	NM_012160.5		c.662A>T	p.Asp221Val	missense	Exon 4 of 9	NP_036292.2
	FBXL4	NR_103836.2		n.843+8907A>T		intron	N/A

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	FBXL4	ENST00000369244.7	TSL:1 MANE Select	c.662A>T	p.Asp221Val	missense	Exon 5 of 10	ENSP00000358247.1
	FBXL4	ENST00000229971.2	TSL:1	c.662A>T	p.Asp221Val	missense	Exon 4 of 9	ENSP00000229971.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461700 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727146

African (AFR) AF: 0.00 AC: 0 AN: 33470

American (AMR) AF: 0.00 AC: 0 AN: 44716

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86240

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000809 AC: 9 AN: 1111882

Other (OTH) AF: 0.0000166 AC: 1 AN: 60392

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

Aug 10, 2017

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

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The NM_012160.4:c.662A>T (NP_036292.2:p.Asp221Val) [GRCH38: NC_000006.12:g.98917570T>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. 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 v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.33	D
BayesDel_noAF	Pathogenic	0.24
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.54	D
Eigen	Uncertain	0.29
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D
M_CAP	Uncertain	0.29	D
MetaRNN	Pathogenic	0.88	D
MetaSVM	Benign	-0.60	T
MutationAssessor	Uncertain	2.1	M
PhyloP100		7.7
PrimateAI	Uncertain	0.71	T
PROVEAN	Pathogenic	-7.6	D
REVEL	Pathogenic	0.68
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0	D
Polyphen		0.36	B
Vest4		0.97
MutPred		0.68		Loss of sheet (P = 0.0457)
MVP		0.80
MPC		0.46
ClinPred		1.0	D
GERP RS		4.4
Varity_R		0.81
gMVP		0.93
Mutation Taster		=11/89	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs1554221189; hg19: chr6-99365446;