Johanson-Blizzard syndrome (JBS) is an autosomal recessive condition characterized by multiple congenital anomalies which include but are not limited to pancreatic insufficiency, hypoplasia/aplasia of the nasal alae, hypodontia, congenital heart defects, deafness, growth retardation, urogenital malformations, short stature, and variable degree of intellectual disability.  The prevalence of JBS was estimated to be 1/250,000 live births in Europe.  

Diagnosis can be made by clinical and genetic evaluations.  Prenatal diagnosis is also possible based on the signs of a beak-like nose and a dilated sigmoid colon at 21 weeks of gestation.  The mainstay of treatment is through oral administration of pancreatic enzymes, thyroid hormone substitution, and nutritional support.  A suitable diet for patients is one that is high in calories and derives 30-40% of its calories from fats.  

JBS is caused by homozygous mutations in the UBR1 gene.  This gene encodes a protein expressed in pancreatic acinar cells at high levels.  Mutations in this gene cause pancreatic enzymes deficiency.  This is because deficiency of this protein may cause the gradual destruction of acinar, thereby leading to pancreatic insufficiency.