Biallelic truncating mutations in TANGO2 cause infancy-onset recurrent metabolic crises with encephalocardiomyopathy
Am J Hum Genet. 2016 Jan 19. pii: S0002-9297(15)00504-2. doi: 10.1016/j.ajhg.2015.12.009. [Epub ahead of print]
|Authors/Editors:||Kremer LS, Distelmaier F, Alhaddad B, Hempel M, Iuso A, Küpper C, Mühlhausen C, Kovacs-Nagy R, Satanovskij R, Graf E, Berutti R, Eckstein G, Durbin R, Sauer S, Hoffmann GF, Strom TM, Santer R, Meitinger T, Klopstock T, Prokisch H, Haack TB.|
Molecular diagnosis of mitochondrial disorders is challenging because of extreme clinical and genetic heterogeneity. By exome sequencing, we identified three different biallelic truncating mutations in TANGO2 in three unrelated individuals with infancy-onset episodic metabolic crises characterized by encephalopathy, hypoglycemia, rhabdomyolysis, arrhythmias, and laboratory findings suggestive of a defect in mitochondrial fatty acid oxidation. Over the course of the disease, all individuals developed global brain atrophy with cognitive impairment and pyramidal signs. TANGO2 (transport and Golgi organization 2) encodes a protein with a putative function in redistribution of Golgi membranes into the endoplasmic reticulum in Drosophila and a mitochondrial localization has been confirmed in mice. Investigation of palmitate-dependent respiration in mutant fibroblasts showed evidence of a functional defect in mitochondrial β-oxidation. Our results establish TANGO2 deficiency as a clinically recognizable cause of pediatric disease with multi-organ involvement.