Acute liver failure in pregnancy associated with maternal MCAD deficiency

In recent years the association between severe pregnancy complications and fetal fatty acid oxidation (FAO) disorders has been reported. However, there are few descriptions of a maternal FAO disorder leading to these complications. We describe acute liver failure associated with an undiagnosed maternal medium-chain acyl-CoA dehydrogenase (MCAD) deficiency. The previously healthy proband presented at the 39th week with an itchy rash, palmar erythema and trace proteinuria; she was admitted onto a maternity ward. Acute fatty liver was suspected from the blood tests and a Caesarean section was performed, delivering a healthy boy. Cord blood samples were taken at delivery as part of an ongoing research project. The analysis of the cord blood sample showed a high concentration of octanoylcarnitine of 2.3 micromol/L (reference <0.1), suggesting a possible fatty acid oxidation disorder. However, subsequent acylcarnitine analyses of the baby's blood showed a normal pattern. The proband was further evaluated by urine organic acids and acylcarnitine profile. Elevated concentrations of hexanoylglycine in urine and octanoylcarnitine in blood spots were found, consistent with a diagnosis of MCAD deficiency. Mutation analyses confirmed that she was homozygous for c.985A>G (K329E). Even though these pregnancy complications are rare and it is not possible to affirm that the proband's acute liver failure was secondary to an undiagnosed MCAD deficiency, it seems likely.