Arthrogryposis-renal dysfunction-cholestasis syndrome

Arthrogryposis-renal dysfunction-cholestasis (ARC) syndrome is an autosomal recessive multisystem disorder that typically presents with arthrogryposis, renal tubular leak and neonatal cholestatic jaundice. It can be accompanied by nervous system abnormalities, deafness, structural cardiac defects, abnormal platelet morphology, recurrent sepsis, ichthyosis and failure to thrive. The three-day-old neonate was admitted for a suspected neuromuscular disorder. On examination, clubfoot, jaundice and hypotonia were found. Laboratory evaluation revealed tubulopathy and cholestasis with normal gamma-glutamyl transferase level. Peripheral blood smear evaluation revealed abnormally giant platelets. Despite the combined enteral and parenteral nutrition, the infant experienced severe failure to thrive. The phenotype of the presented neonate is consistent with ARC syndrome. Sequencing of the causal genes revealed a homozygous consensus splice site VPS33B mutation (c.498+1G>T), confirming the clinical diagnosis.