Dataset Information

Intrafamilial variability for novel TAZ gene mutation: Barth syndrome with dilated cardiomyopathy and heart failure in an infant and left ventricular noncompaction in his great-uncle.

ABSTRACT:

Background

The tafazzin gene (TAZ) is located at Xq28 and encodes a protein involved in the transacylation of cardiolipin, an essential mitochondrial phospholipid. Mutations in TAZ are associated with Barth syndrome (BTHS), the X-linked recessive condition with dilated cardiomyopathy, skeletal myopathy, growth retardation, neutropenia and organic aciduria. TAZ mutations also contribute to left ventricular noncompaction (LVNC), a cardiomyopathy characterized by loose, trabeculated myocardium.

Case report

We report a family with a novel TAZ mutation and the clinical spectrum from severe BTHS in an infant to skeletal myopathy with LVNC in an adult, the oldest individual with BTHS reported. The proband is a 51-year-old male with muscle weakness since early childhood. He remained stable until the age of 43. His initial evaluations found LVNC and borderline neutropenia with no elevation of urine 3-methylglutaconic acid. The proband's great nephew is a 3-year-old who presented at birth with poor feeding, hypotonia, lactic acidosis and hypoglycemia. At three months he was admitted with failure to thrive, lethargy and respiratory distress due to heart failure. Cardiac studies revealed dilated cardiomyopathy with a spongiform trabeculated pattern of the left ventricle. Laboratory studies showed cyclic neutropenia and elevated urine 3-methylglutaconic and 3-methylglutaric acids. At age 11months the patient had a heart transplant. We conducted sequence analysis of the TAZ gene for two affected individuals, the proband first and then his great-nephew. A novel, hemizygous nonsense mutation in TAZ exon 7 (c.583G>T, p.Gly195X) was detected.

Conclusion

At his current age of 51years-old, the proband is the oldest surviving individual reported with a confirmed molecular diagnosis and features of Barth syndrome. Further studies will be conducted to identify the genetic modifying factor(s) associated with the wide phenotypic range seen in this family.

SUBMITTER: Ronvelia D

PROVIDER: S-EPMC3483384 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature

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Publications

Intrafamilial variability for novel TAZ gene mutation: Barth syndrome with dilated cardiomyopathy and heart failure in an infant and left ventricular noncompaction in his great-uncle.

Ronvelia Diti D Greenwood Jaclyn J Platt Julia J Hakim Simin S Zaragoza Michael V MV

Molecular genetics and metabolism 20120918 3

<h4>Background</h4>The tafazzin gene (TAZ) is located at Xq28 and encodes a protein involved in the transacylation of cardiolipin, an essential mitochondrial phospholipid. Mutations in TAZ are associated with Barth syndrome (BTHS), the X-linked recessive condition with dilated cardiomyopathy, skeletal myopathy, growth retardation, neutropenia and organic aciduria. TAZ mutations also contribute to left ventricular noncompaction (LVNC), a cardiomyopathy characterized by loose, trabeculated myocard ...[more]

PMID: 23031367

Similar Datasets

Project description:BackgroundLess than 40% of patients with dilated cardiomyopathy (DCM) have a pathogenic/likely pathogenic genetic variant identified. TBX20 has been linked to congenital heart defects; although an association with left ventricular noncompaction (LVNC) and DCM has been proposed, it is still considered a gene with limited evidence for these phenotypes. This study sought to investigate the association between the TBX20 truncating variant (TBX20tv) and DCM/LVNC.MethodsTBX20 was sequenced by next-generation sequencing in 7463 unrelated probands with a diagnosis of DCM or LVNC, 22 773 probands of an internal comparison group (hypertrophic cardiomyopathy, channelopathies, or aortic diseases), and 124 098 external controls (individuals from the gnomAD database). Enrichment of TBX20tv in DCM/LVNC was calculated, cosegregation was determined in selected families, and clinical characteristics and outcomes were analyzed in carriers.ResultsTBX20tv was enriched in DCM/LVNC (24/7463; 0.32%) compared with internal (1/22 773; 0.004%) and external comparison groups (4/124 098; 0.003%), with odds ratios of 73.23 (95% CI, 9.90-541.45; P<0.0001) and 99.76 (95% CI, 34.60-287.62; P<0.0001), respectively. TBX20tv was cosegregated with DCM/LVNC phenotype in 21 families for a combined logarythm of the odds score of 4.53 (strong linkage). Among 57 individuals with TBX20tv (49.1% men; mean age, 35.9±20.8 years), 41 (71.9%) exhibited DCM/LVNC, of whom 14 (34.1%) had also congenital heart defects. After a median follow-up of 6.9 (95% CI, 25-75:3.6-14.5) years, 9.7% of patients with DCM/LVNC had end-stage heart failure events and 4.8% experienced malignant ventricular arrhythmias.ConclusionsTBX20tv is associated with DCM/LVNC; congenital heart defect is also present in around one-third of cases. TBX20tv-associated DCM/LVNC is characterized by a nonaggressive phenotype, with a low incidence of major cardiovascular events. TBX20 should be considered a definitive gene for DCM and LVNC and routinely included in genetic testing panels for these phenotypes.

Dataset Information

Intrafamilial variability for novel TAZ gene mutation: Barth syndrome with dilated cardiomyopathy and heart failure in an infant and left ventricular noncompaction in his great-uncle.

Background

Case report

Conclusion

Publications

Intrafamilial variability for novel TAZ gene mutation: Barth syndrome with dilated cardiomyopathy and heart failure in an infant and left ventricular noncompaction in his great-uncle.

Similar Datasets

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