8-95035527-T-C
Variant summary
Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP5BP4BS2
The NM_152416.4(NDUFAF6):āc.371T>Cā(p.Ile124Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000384 in 1,613,100 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_152416.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -4 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000330 AC: 5AN: 151502Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000922 AC: 23AN: 249420Hom.: 0 AF XY: 0.0000665 AC XY: 9AN XY: 135338
GnomAD4 exome AF: 0.0000390 AC: 57AN: 1461482Hom.: 2 Cov.: 31 AF XY: 0.0000440 AC XY: 32AN XY: 727036
GnomAD4 genome AF: 0.0000330 AC: 5AN: 151618Hom.: 0 Cov.: 32 AF XY: 0.0000405 AC XY: 3AN XY: 74008
ClinVar
Submissions by phenotype
Mitochondrial complex 1 deficiency, nuclear type 17 Pathogenic:2
The missense variant p.I124T in NDUFAF6 (NM_152416.4) has been reported previously in patients affected with mitochondrial disease in compound heterozygous state (Kohda M, et al). It has been submitted to ClinVar as Variant of uncertain significance. The variant has been detected in homozygous state in two affected siblings with Leigh disease within one of the submitting labs in ClinVar. The p.I124T missense variant is predicted to be damaging by both SIFT and PolyPhen2. The nucleotide c.371 in NDUFAF6 is predicted conserved by GERP++ and PhyloP across 100 vertebrates. For these reasons, this variant has been classified as Likely Pathogenic. -
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not provided Pathogenic:2
This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 124 of the NDUFAF6 protein (p.Ile124Thr). This variant is present in population databases (rs201732170, gnomAD 0.08%). This missense change has been observed in individuals with clinical features of mitochondrial complex I deficiency (PMID: 26741492, 30642748, 31967322, 32348839). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 214212). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt NDUFAF6 protein function with a negative predictive value of 80%. For these reasons, this variant has been classified as Pathogenic. -
In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 26741492, 28429146, 30642748, 31967322, 32348839, 34988976, 35094435, 35664867) -
Leigh syndrome Uncertain:2
The homozygous p.Ile124Thr variant in NDUFAF6 was identified by our study in two siblings with Leigh syndrome. The p.Ile124Thr variant in NDUFAF6 has been reported in 2 Japanese individuals with Leigh syndrome (PMID: 26741492) and has been identified in 0.07952% (15/18862) of East Asian chromosomes and 0.01949% (6/30780) of South Asian chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs201732170). This variant has also been reported as a VUS in ClinVar (Variation ID: 214212). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. Computational prediction tools and conservation analyses do not provide strong support for or against an impact to the protein. The presence of this variant in combination with 2 variants reported pathogenic in the literature and OMIM and in 2 individuals with Leigh syndrome increases the likelihood that the p.Ile124Thr variant is pathogenic. In summary, while there is some suspicion for a pathogenic role, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: PM2, PM3 (Richards 2015). -
This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at