Neonatal Graves' disease with unusual metabolic association from presentation to resolution

Neonatal Graves' disease is a rare disorder seen in 1 in 25,000 births and in 1% of the offspring of mothers with either established or cured Graves' disease. This is due to transplacental passage of thyroid-stimulating immunoglobulins (TSIs). A higher TSI titre in maternal serum makes hyperthyroidism more likely in the fetus or newborn; however, not all fetuses born by women with positive TSIs develop overt hyperthyroidism. In spite of its rarity, its serious nature (if not treated) and its association with multisystem abnormalities justifies careful clinical screening and management. We report a preterm 30 weeks neonate with neonatal thyrotoxicosis secondary to untreated maternal Graves' disease who, in addition to the typical hyperthyroidism symptoms, had unusual metabolic associations of neonatal cholestasis and hyperammonaemia. The patient was treated accordingly with a good response. This report supports previous reports on the association between neonatal hyperthyroidism and cholestatic liver disease. However, it is the second case report to describe the unusual association of hyperammonaemia and neonatal Graves' disease.