X-154419746-G-T

Position:

• chrX-154419746-G-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1 PM2 PP3_Strong PP5_Moderate

The NM_000116.5(TAFAZZIN):​c.583G>T​(p.Gly195Ter) variant causes a stop gained, splice region change. The variant was absent in control chromosomes in GnomAD project. 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 (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 24)
• Consequence: TAFAZZIN NM_000116.5 stop_gained, splice_region
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 5.38

Genes affected

TAFAZZIN (HGNC:11577): (tafazzin, phospholipid-lysophospholipid transacylase) This gene encodes a protein that is expressed at high levels in cardiac and skeletal muscle. Mutations in this gene have been associated with a number of clinical disorders including Barth syndrome, dilated cardiomyopathy (DCM), hypertrophic DCM, endocardial fibroelastosis, and left ventricular noncompaction (LVNC). Multiple transcript variants encoding different isoforms have been described. A long form and a short form of each of these isoforms is produced; the short form lacks a hydrophobic leader sequence and may exist as a cytoplasmic protein rather than being membrane-bound. Other alternatively spliced transcripts have been described but the full-length nature of all these transcripts is not known. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant X-154419746-G-T is Pathogenic according to our data. Variant chrX-154419746-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 559336.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chrX-154419746-G-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TAFAZZIN	NM_000116.5	c.583G>T	p.Gly195Ter	stop_gained, splice_region_variant	7/11	ENST00000601016.6	NP_000107.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TAFAZZIN	ENST00000601016.6	c.583G>T	p.Gly195Ter	stop_gained, splice_region_variant	7/11	1	NM_000116.5	ENSP00000469981

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 24

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

3-Methylglutaconic aciduria type 2 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Jan 17, 2022

Variant summary: TAZ c.583G>T (p.Gly195X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been reported in HGMD in association with Barth Syndrome. The variant was absent in 183336 control chromosomes. c.583G>T has been reported in the literature in individuals affected with Barth Syndrome (Ronvelia_2012, Lee_2013). One publication also reports the variant to result in the skipping of 12 amino acid in the longest isoform (Lee_2013). One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. One laboratory classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Mayo Clinic Laboratories, Mayo Clinic

Feb 22, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	47
DANN	Uncertain	0.99
FATHMM_MKL	Uncertain	0.94	D
M_CAP	Pathogenic	0.94	D
MutationTaster	Benign	1.0	A;A;A;D;D;D
Vest4		0.96, 0.99
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.66		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.66		Position offset: 0

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

Publications

LitVar

Other links and lift over

dbSNP: rs878853656; hg19: chrX-153648085;