By Aimee Molineux Reviewed by Emily Henderson, B.Sc. Johanson–Blizzard syndrome (JBS) is a rare autosomal recessive condition caused by homozygous and compound heterozygous mutations in the UBR1 gene. Until 2005, the genetic abnormality that caused the syndrome was unknown. Multisystem involvement and facial dysmorphic characteristics are hallmarks of this syndrome. Bilateral severe to profound sensorineural...
