Metrics details. The medical records of all patients with BTHS living in France were identified in multiple sources and reviewed. We identified 16 BTHS pedigrees that included 22 patients. TAZ mutations were observed in 15 pedigrees. The estimated incidence of BTHS was 1. The median age at presentation was 3. Eleven patients died at a median age of 5. Fourteen patients presented with cardiomyopathy, and cardiomyopathy was documented in 20 during follow-up.
Left ventricular systolic function was very poor during the first year of life and tended to normalize over time. Nineteen patients had neutropenia. Metabolic investigations revealed inconstant moderate 3-methylglutaconic aciduria and plasma arginine levels that were reduced or in the low-normal range. This survey found that BTHS outcome was affected by cardiac events and by a risk of infection that was related to neutropenia.
(mh=_4xT5TjTg6qVPGuK)0.jpg "Babes Béziers")
Modern management of heart failure and prevention of infection in infancy may improve the survival of patients with BTHS without the need for heart transplantation. This syndrome is characterized by cardiomyopathy, neutropenia, skeletal myopathy and growth delay.
While clinical symptoms are usually present early in infancy [ 2 ], the age at presentation and the features of BTHS vary significantly among patients [ 3 ]. This gene encodes the Tafazzin protein, which is involved in the remodelling of cardiolipin, an essential component of the mitochondrial inner membrane that is necessary for proper function of the respiratory chain [ 5 , 6 ].
No genotype-phenotype correlation has been described to date [ 7 ]. Currently, there are recorded cases of BTHS worldwide [ 8 ] and several surveys have been published in the last 10 years.
