A late-diagnosed phenylketonuria case presenting with autism spectrum disorder in early childhood

Abstract

SUMMARY: Mazlum B, Anlar B, Kalkanoğlu-Sivri HS, Karlı-Oğuz K, Özusta Ş,Ünal F. A late-diagnosed case presenting with autism spectrum disorder inearly childhood. Turk J Pediatr 2016; 58: 318-322.Phenylketonuria is one of the most prevalent autosomal recessive hereditarydisorders in Turkey. If untreated, it results in severe brain damage and canalso be associated with autism in certain patients. We present a three-year oldboy who exhibited the symptoms of autism and was subsequently diagnosedwith phenylketonuria. This case illustrates that because the majority ofautism cases are idiopathic, an occasional patient with a metabolic disordermight be overlooked especially in the era of newborn screening. We alsodiscuss the possible pathogenetic processes leading to autistic symptomsin phenylketonuria, and wish to draw attention to the possibility of casesmissed in the screening program because of less than 100% coverage orinsufficient food intake before blood sampling. Clinicians should keep in mindthe possibility of treatable disorders in children with autism even when suchdisorders appear unlikely.