Rare association of septic arthritis with neonatal diabetes in a patient with PDX-1 mutation

Abstract

We present a 58-day-old male infant with neonatal diabetes and septic arthritis of hip. He was born of a consanguineous marriage at 35 weeks of gestation and was asymptomatic till presentation. Family history revealed his older sibling had suffered from meningitis and a second sibling had neonatal diabetes (died due to an unknown infection). Our patient underwent arthroscopy for septic arthritis and symptoms resolved after antibiotic therapy. Genetic testing was performed for the lipopolysaccharide-responsive beige-like anchor (LRBA) mutation (known to be associated with neonatal diabetes and autoimmune disorders); however, the result revealed a homozygous mutation in PDX-1 gene which is known to cause neonatal diabetes with or without exocrine pancreatic insufficiency. Our case suggests that in neonatal diabetes with atypical infections, genetic causes other than LRBA mutation, like PDX-1 mutation, may be suspected. A genetic diagnosis aids both in treatment and prognostication of neonatal diabetes.