Subdural and retinal haemorrhages in young children without an appropriate history of trauma strongly suggest non-accidental injury. Similar features are occasionally found in patients with glutaric aciduria type 1 (GA1), a rare inborn error of metabolism, and have led to the misdiagnosis of non-accidental injury.1-3 When and how should this condition be sought in cases of suspected child abuse?

GA1 is an autosomal recessive disorder caused by deficiency of the enzyme glutaryl-CoA dehydrogenase. Commonly it presents before age 18 months with a sudden onset of encephalopathy, following which the child has a severe and persistent movement disorder. Before this there may have been episodes of irritability or mild encephalopathy with no sequelae. Clinical examination at this stage often shows macrocephaly, and cerebral imaging may show bilateral frontotemporal atrophy or widening of the Sylvian fissure, with or without subdural effusions (fig 1). Following the catastrophic encephalopathic …