title: Atypical Clinical Presentations of TAZ Mutations: An Underdiagnosed Cause of Growth Retardation?
abstract: Barth syndrome is known as a highly recognizable X-linked disorder typically presenting with the three hallmarks: (left ventricular non-compaction) cardiomyopathy, neutropenia, and 3-methylglutaconic aciduria. Furthermore, growth retardation, mild skeletal myopathy, and specific facial features as well as mitochondrial dysfunction in muscle are frequently seen. Underlying mutations are found in TAZ and lead to defective cardiolipin remodeling.Here, we report atypical clinical manifestations of TAZ mutations in two male patients initially presenting with growth retardation and very mild skeletal myopathy. As other phenotypic hallmarks were missing, Barth syndrome had not been suspected in these patients. One of them has been incidentally diagnosed in the frame of an in-depth cardiolipin research analysis, while the underlying genetic defect was unexpectedly identified in the second one by exome sequencing.
  
  
  CONCLUSIONS
  These cases underline that TAZ mutations might well be an underdiagnosed cause of skeletal myopathy and growth retardation and do not necessarily manifest with the full clinical picture of Barth syndrome.
authors.affiliation: Department of Neuropediatrics, University Children's Hospital, Bochum, Germany.|Center for Rare Diseases (CeSER), Ruhr University Bochum, Bochum, Germany.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Thiels
authors.affiliation: Department of Pediatrics, Landeskrankenhaus Bregenz, Bregenz, Austria.
authors.forename: Martin
authors.initials: M
authors.lastname: Fleger
authors.affiliation: Department of Pediatrics, Landeskrankenhaus Bregenz, Bregenz, Austria.|Division of Metabolism, University Children's Hospital Zürich, Zürich, Switzerland.
authors.forename: Martina
authors.initials: M
authors.lastname: Huemer
authors.affiliation: Department of Paediatrics, Nijmegen Center for Mitochondrial Disorders, Radboud UMC, Nijmegen, The Netherlands.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Rodenburg
authors.affiliation: Laboratory Genetic Metabolic Diseases, AMC, Amsterdam, The Netherlands.
authors.forename: Frederic M
authors.initials: FM
authors.lastname: Vaz
authors.affiliation: Laboratory Genetic Metabolic Diseases, AMC, Amsterdam, The Netherlands.
authors.forename: Riekelt H
authors.initials: RH
authors.lastname: Houtkooper
authors.affiliation: Institute of Human Genetics, Technische Universität München, Munich, Germany.|Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Munich, Germany.
authors.forename: Tobias B
authors.initials: TB
authors.lastname: Haack
authors.affiliation: Institute of Human Genetics, Technische Universität München, Munich, Germany.|Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Munich, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Prokisch
authors.affiliation: Department of Pediatrics, Salzburger Landeskliniken (SALK), Paracelsus Medical University (PMU), Salzburg, Austria.
authors.forename: René G
authors.initials: RG
authors.lastname: Feichtinger
authors.affiliation: Department of Neuropediatrics, University Children's Hospital, Bochum, Germany.|Center for Rare Diseases (CeSER), Ruhr University Bochum, Bochum, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lücke
authors.affiliation: Department of Pediatrics, Salzburger Landeskliniken (SALK), Paracelsus Medical University (PMU), Salzburg, Austria.
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Mayr
authors.affiliation: Department of Paediatrics, Nijmegen Center for Mitochondrial Disorders, Radboud UMC, Nijmegen, The Netherlands. s.wortmann-hagemann@salk.at.|Department of Pediatrics, Salzburger Landeskliniken (SALK), Paracelsus Medical University (PMU), Salzburg, Austria. s.wortmann-hagemann@salk.at.
authors.forename: Saskia B
authors.initials: SB
authors.lastname: Wortmann
keywords: 3-Methylglutaconic aciduria; Barth syndrome; Failure to thrive; Gowers’ sign; Myopathy