Contiguous Gene Deletion of Chromosome Xp in Three Families Encompassing OTC, RPGR and TSPAN7 Genes

Shailly Jain-Ghai,Stephanie Sk

Abstract

Ornithine transcarbamylase deficiency (OTCD) is the most common urea cycle disorder. The classic presentation in males is hyperammonemic encephalopathy in the early neonatal period. Given the X-linked inheritance of OTCD, presentation in females is highly variable. We present three families with different contiguous gene deletions on chromosome Xp. Deletion of RPGR, OTC and TSPAN7 is common to all three families in our series. These cases highlight the variable phenotype in manifesting OTCD female carriers, the complexity of OTCD management and complex issues surrounding the option of liver transplantation when multiple other genetic factors play a role.