Survival of a Male Infant with a Familial Xp11.4 Deletion Causing Ornithine Transcarbamylase Deficiency.

Ornithine transcarbamylase (OTC) deficiency is well known to cause severe neonatal hyperammonemia in males with absent enzyme activity. In families with large deletions of the X chromosome involving OTC and other contiguous genes, male infants appear to have an even more severe course. Notably, there are no published reports of these males surviving to liver transplant, even in cases where the diagnosis was known or suspected at birth. We describe two male newborns and their mother who all have a 1.5-Mb deletion of Xp11.4 encompassing the genes TSPAN7, OTC, and part of RPGR. The first child succumbed to his illness on his fourth day of life. His younger brother was diagnosed prenatally, and with early aggressive treatment, he survived the neonatal period. He suffered multiple life-threatening complications but stabilized and received a liver transplant at 7 months of age. This report demonstrates both the possibility of survival and the complications in caring for these patients.