chrX-154411856-G-T
Variant summary
Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM1
The NM_000116.5(TAFAZZIN):c.13G>T(p.Val5Leu) variant causes a missense change. The variant allele was found at a frequency of 0.0000159 in 1,197,370 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 2 hemizygotes in GnomAD. Variant has been reported in ClinVar as Uncertain significance (★★).
Frequency
Consequence
NM_000116.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 2 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
TAFAZZIN | NM_000116.5 | c.13G>T | p.Val5Leu | missense_variant | Exon 1 of 11 | ENST00000601016.6 | NP_000107.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000178 AC: 2AN: 112372Hom.: 0 Cov.: 24 AF XY: 0.0000290 AC XY: 1AN XY: 34538
GnomAD3 exomes AF: 0.0000339 AC: 5AN: 147643Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 47991
GnomAD4 exome AF: 0.0000157 AC: 17AN: 1084998Hom.: 0 Cov.: 31 AF XY: 0.00000281 AC XY: 1AN XY: 356184
GnomAD4 genome AF: 0.0000178 AC: 2AN: 112372Hom.: 0 Cov.: 24 AF XY: 0.0000290 AC XY: 1AN XY: 34538
ClinVar
Submissions by phenotype
not specified Uncertain:1
Variant classified as Uncertain Significance - Favor Pathogenic. The Val5Leu var iant has not been reported in the literature but has been identified in an Ashke nazi Jewish individual with mild DCM and muscle weakness as well as two family m embers (brother and mother) with similar features. The variant was absent from 332 Ashkenazi Jewish control chromosomes, which is consistent with a pathogenic role (LMM unpublished data). Valine (Val) at position 5 is conserved across mamm als and amphibians, but is not 100% conserved across more evolutionary distant s pecies (fruitfly and yeast), reducing the likelihood that the change is pathogen ic. Valine and Leucine have similar biochemical properties, which also suggest t hat the change may not severely affect the protein. However, most TAZ variants a re pathogenic and cause Barth syndrome (www.barthsyndrome.org). In summary, thi s variant likely causes or contributes to disease but additional data is needed to establish this with certainty. Please note that a new biochemical test is ava ilable that can help establish a diagnosis of Barth syndrome (see recommendation s section). -
3-Methylglutaconic aciduria type 2 Uncertain:1
This sequence change replaces valine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 5 of the TAZ protein (p.Val5Leu). This variant is present in population databases (rs397515737, gnomAD 0.08%). This variant has not been reported in the literature in individuals affected with TAZ-related conditions. ClinVar contains an entry for this variant (Variation ID: 42253). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
not provided Uncertain:1
A variant of uncertain significance has been identified in the TAZ gene. The V5L variant has not been published as pathogenic or been reported as benign to our knowledge. However, it is classified as a variant of uncertain significance in ClinVar by a different clinical laboratory, where it was observed in an Ashkenazi Jewish individual with mild DCM and muscle weakness, and segregated with similar features in this individual's mother and brother (ClinVar SCV000058726.4; Landrum et al., 2016). The V5L variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). Additionally, this substitution occurs at a position that is conserved across species and in silico analysis predicts this variant is probably damaging to the protein structure/function. Nevertheless, the V5L variant is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties. Furthermore, this variant lacks observation in a significant number of affected individuals, large segregation studies, and functional evidence, which would further clarify its pathogenicity. -
Cardiovascular phenotype Uncertain:1
The p.V5L variant (also known as c.13G>T), located in coding exon 1 of the TAZ gene, results from a G to T substitution at nucleotide position 13. The valine at codon 5 is replaced by leucine, an amino acid with highly similar properties. Based on data from gnomAD, the T allele has an overall frequency of 0.00387% (5/147643) total alleles studied, with 0 hemizygote(s) observed. The highest observed frequency was 0.07389% (5/6767) of Ashkenazi Jewish alleles. In addition, this variant has been identified in apparently unaffected hemizygous individuals in our laboratory (Ambry internal data). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at