A case of potential inborn error of metabolism as a cause of young onset psychosis

Introduction: Young onset psychosis has poor prognosis, and inborn errors of metabolism (IEM) can be easily missed. There is scarce information regarding IEM and young onset psychosis in Malaysia. Case Report: A 15-year-old Malay girl presented at the age of 8 years with a history of intellectual disability and neuro-regression, subsequently developing psychotic and obsessive-compulsive symptoms several years later. Organic workup revealed elevated lactate levels. Urine organic acid chromatogram revealed a moderate peak of lactate however most other investigations were normal. As MRI brain is normal and there are no neurological signs it appears less likely there is an underlying IEM-related aetiology for psychosis. Discussion: Various IEMs can be related to psychosis however the incidence is very low and quality of evidence is poor. Thus, any psychiatric presentation, particularly with suggestive clinical signs, should warrant an organic (including IEM) workup since these causes are potentially reversible with supplementation