TY - JOUR TI - Evidence for treatable inborn errors of metabolism in a cohort of 187 Greek patients with autism spectrum disorder (ASD) AU - Spilioti, Martha AU - Evangeliou, Athanasios E. AU - Tramma, Despoina and AU - Theodoridou, Zoe AU - Metaxas, Spyridon AU - Michailidi, Eleni AU - Bonti, AU - Eleni AU - Frysira, Helen AU - Haidopoulou, A. AU - Asprangathou, Despoina AU - and Tsalkidis, Aggelos J. AU - Kardaras, Panagiotis AU - Wevers, Ron A. AU - and Jakobs, Cornelis AU - Gibson, K. Michael JO - Frontiers in Human Neuroscience PY - 2013 VL - 7 TODO - null SP - null PB - Frontiers Research Foundation SN - null TODO - 10.3389/fnhum.2013.00858 TODO - autism; inborn errors of metabolism; biotin; ketogenic diet; 3-hydroxyisovaleric acid; Lesch-Nyhan disease; succinic semialdehyde dehydrogenase deficiency; phenylketonuria TODO - We screened for the presence of inborn errors of metabolism (IEM) in 187 children (105 males; 82 females, ages 4-14 years old) who presented with confirmed features of autism spectrum disorder (ASD). Twelve patients (7%) manifested increased 3-hydroxyisovaleric acid (3-OH-IVA) excretion in urine, and minor to significant improvement in autistic features was observed in seven patients following supplementation with biotin. Five diagnoses included: Lesch Nyhan syndrome (2), succinic semialdehyde dehydrogenase (SSADH) deficiency (2), and phenylketonuria (1) (2.7%). Additional metabolic disturbances suggestive of IEMs included two patients whose increased urine 3-OH-IVA was accompanied by elevated methylcitrate and lactate in sera, and 30 patients that showed abnormal glucose-loading tests. In the latter group, 16/30 patients manifested increased sera beta hydroxybutyrate (b-OH-b) production and 18/30 had a paradoxical increase of sera lactate. Six patients with elevated b-OH-b in sera showed improved autistic features following implementation of a ketogenic diet (KD). Five patients showed decreased serum ketone body production with glucose loading. Twelve of 187 patients demonstrated non-specific MRI pathology, while 25/187 had abnormal electroencephalogram (EEG) findings. Finally, family history was positive for 22/187 patients (1st or 2nd degree relative with comparable symptomatology) and consanguinity was documented for 12/187 patients. Our data provide evidence for a new biomarker (3-OH-IVA) and novel treatment approaches in ASD patients. Concise 1 sentence take-home message: Detailed metabolic screening in a Greek cohort of ASD patients revealed biomarkers (urine 3-hydroxyisovaleric acid and serum b-OH-b) in 7% (13/187) of patients for whom biotin supplementation or institution of a KD resulted in mild to significant clinical improvement in autistic features. ER -