Johanson-Blizzard syndrome with mild phenotypic features confirmed by UBR1 gene testing

Johanson-Blizzard syndrome (JBS) is a rare autosomal recessive condition associated with exocrine pancreatic insufficiency, and is characterized by hypoplastic nasal alae, mental retardation, sensorineural hearing loss, short stature, scalp defects, dental abnormalities and abnormal hair patterns. Growth hormone deficiency, hypopituitarism, and impaired glucagon secretion response to insulin-induced hypoglycemia have been reported. Congenital heart defects have also been described in this condition. Mental retardation is typically moderate to severe in patients with JBS; however, normal intelligence can occur. In the pancreas, there is a selective defect of acinar tissue, whereas the islets of Langerhans and ducts are preserved. Diabetes has been reported in older children, suggesting the progressive nature of pancreatic disease. The molecular basis of JBS has recently been mapped to chromosome 15q15-q21 with identified mutations in the UBR1 gene. We report the case of a 7-year-old female with pancreatic insufficiency and mild phenotypic features, in whom the diagnosis of JBS was established using recently described molecular testing for the UBR1 gene.