Developmental Medicine & Child Neurology

Original Articles

Mitochondrial dysfunction in autism spectrum disorders: a population-based study

Oliveira  a1 c1, Diogo  a2, Grazina  a3, Garcia  a2, Ataíde  a4, Marques  a1, Miguel  a4, Borges  a5, AM Vicente  a6 and CR Oliveira  a3
a1 Outpatient Clinic of Autism, Centro de Desenvolvimento da Criança, Hospital Pediátrico de Coimbra, Portugal.
a2 Metabolic Clinic, Hospital Pediátrico de Coimbra, Portugal.
a3 Biochemistry Institute, Faculdade de Medicina de Coimbra, Portugal.
a4 Outpatient Clinic of Autism, Direcção Regional de Educação da Região Centro, Portugal.
a5 Centro de Desenvolvimento da Criança Hospital Pediátrico de Coimbra, Portugal.
a6 Instituto Gulbenkian de Ciência, Oeiras, Portugal.


A minority of cases of autism has been associated with several different organic conditions, including bioenergetic metabolism deficiency. In a population-based study, we screened associated medical conditions in a group of 120 children with autism (current age range 11y 5mo to 14y 4mo, mean age 12y 11mo [SD 9.6mo], male:female ratio 2.9:1). Children were diagnosed using Diagnostic and Statistical Manual of Mental Disorders criteria, the Autism Diagnostic Interview – Revised, and the Childhood Autism Rating Scale; 76% were diagnosed with typical autism and 24% with atypical autism. Cognitive functional level was assessed with the Griffiths scale and the Wechsler Intelligence Scale for Children and was in the normal range in 17%. Epilepsy was present in 19 patients. Plasma lactate levels were measured in 69 patients, and in 14 we found hyperlactacidemia. Five of 11 patients studied were classified with definite mitochondrial respiratory chain disorder, suggesting that this might be one of the most common disorders associated with autism (5 of 69; 7.2%) and warranting further investigation.

(Accepted May 19 2004)

c1 Centro de Desenvolvimento da Criança, Hospital Pediátrico de Coimbra, 3000-076 Coimbra, Portugal. E-mail: