X-154412203-C-T

Position:

• chrX-154412203-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000116.5(TAFAZZIN):​c.227C>T​(p.Pro76Leu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 25)
• Consequence: TAFAZZIN NM_000116.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.25

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]

TAFAZZIN (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a chain Tafazzin (size 261) in uniprot entity TAZ_HUMAN there are 6 pathogenic changes around while only 0 benign (100%) in NM_000116.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.978

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TAFAZZIN	NM_000116.5	c.227C>T	p.Pro76Leu	missense_variant	2/11	ENST00000601016.6	NP_000107.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TAFAZZIN	ENST00000601016.6	c.227C>T	p.Pro76Leu	missense_variant	2/11	1	NM_000116.5	ENSP00000469981.1

Frequencies

GnomAD3 genomes Cov.: 25

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 25

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

3-Methylglutaconic aciduria type 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 09, 2019

This sequence change replaces proline with leucine at codon 76 of the TAZ protein (p.Pro76Leu). The proline residue is highly conserved and there is a moderate physicochemical difference between proline and leucine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with TAZ-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.47
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.78	.;.;.;.;.;D;D
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.99	.;D;D;.;D;D;D
M_CAP	Pathogenic	0.80	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.5	.;M;M;.;M;M;.
PrimateAI	Pathogenic	0.80	T
PROVEAN	Pathogenic	-8.8	.;.;D;.;.;.;D
REVEL	Pathogenic	0.93
Sift	Uncertain	0.0020	.;.;D;.;.;.;D
Sift4G	Uncertain	0.0040	D;D;D;D;D;D;D
Polyphen		1.0, 1.0	.;D;D;.;D;D;.
Vest4		0.78, 0.77, 0.68, 0.66
MutPred		0.85		.;Loss of disorder (P = 0.0837);Loss of disorder (P = 0.0837);.;Loss of disorder (P = 0.0837);Loss of disorder (P = 0.0837);Loss of disorder (P = 0.0837);
MVP		0.97
ClinPred		1.0	D
GERP RS		4.1
Varity_R		0.95
gMVP		1.0

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: rs878853654; hg19: chrX-153640540;