02611nas a2200313   4500008004100000022001400041245017200055210006900227260001600296300001000312490000700322520157100329100002801900700002301928700001601951700002401967700002501991700002102016700001902037700002202056700002102078700002102099700002002120700002202140700001902162700002102181700002802202856006702230       2014                        eng d  a1098-100400aTwo Novel Mutations in the BCKDK Gene (Branched-Chain Keto-Acid Dehydrogenase Kinase) are Responsible of a Neurobehavioral Deficit in two Pediatric Unrelated Patients.0 aTwo Novel Mutations in the BCKDK Gene BranchedChain KetoAcid Deh  c2014 Jan 21  a470-70 v353 aInactivating mutations in the BCKDK gene, which codes for the kinase responsible for the negative regulation of the branched-chain keto-acid dehydrogenase complex (BCKD), have recently been associated with a form of autism in three families. In this work, two novel exonic BCKDK mutations, c.520C>G/p.R174G and c.1166T>C/p.L389P, were identified at the homozygous state in two unrelated children with persistently reduced body fluid levels of branched-chain amino acids (BCAAs), developmental delay, microcephaly and neurobehavioral abnormalities. Functional analysis of the mutations confirmed the missense character of the c.1166T>C change and showed a splicing defect r.[520c>g;521_543del]/p.R174Gfs1*, for c.520C>G due to the presence of a new donor splice site. Mutation p.L389P showed total loss of kinase activity. Moreover, patient-derived fibroblasts showed undetectable (p.R174Gfs1*) or barely detectable (p.L389P) levels of BCKDK protein and its phosphorylated substrate (phospho-E1α), resulting in increased BCKD activity and the very rapid BCAA catabolism manifested by the patients’ clinical phenotype. Based on these results, a protein-rich diet plus oral BCAA supplementation was implemented in the patient homozygous for p.R174Gfs1*. This treatment normalized plasma BCAA levels and improved growth, developmental and behavioral variables. Our results demonstrate that BCKDK mutations can result in neurobehavioral deficits in humans and support the rationale for dietary intervention. This article is protected by copyright. All rights reserved.1 aGarcía-Cazorla, Angels1 aOyarzabal, Alfonso1 aFort, Joana1 aRobles, Concepción1 aCastejón, Esperanza1 aRuiz-Sala, Pedro1 aBodoy, Susanna1 aMerinero, Begoña1 aLopez-Sala, Anna1 aDopazo, Joaquín1 aNunes, Virginia1 aUgarte, Magdalena1 aArtuch, Rafael1 aPalacín, Manuel1 aRodríguez-Pombo, Pilar  uhttp://onlinelibrary.wiley.com/doi/10.1002/humu.22513/abstract