Novel ubiquitin protein ligase E3 component N-Recognin 1 gene mutation in johanson–blizzard syndrome: Development of hypothyroidism during infancy

Johanson–Blizzard syndrome (JBS) is a rare autosomal recessive disorder, characterized by exocrine pancreatic deficiency and a wide range of other abnormalities. Here, we present an infant with failure to thrive, exocrine pancreatic deficiency, developmental delay, cutis aplasia on the scalp, aplasia of alae nasi, hypospadias, and hypothyroidism. Molecular studies revealed a novel homozygous nonsense mutation in exon exon 22 of the ubiquitin protein ligase E3 component N-recognin 1 gene, which confirmed the diagnosis of JBS. In conclusion, it was reported that mutations were mostly family-specific and the same mutation was rarely present in another family. Autosomal recessive diseases are more common in Turkey than in other European countries due to the high frequency of consanguineous marriage. Investigations revealed deafness and congenital hypothyroidism.