A biallelic 36-bp insertion in PIBF1 is associated with Joubert syndrome

Biallelic pathogenic variants in PIBF1 have been identified as one of the genetic etiologies of Joubert syndrome. We report a two-year-old girl with global developmental delay, facial dysmorphism, hypotonia, enlarged cystic kidneys, molar tooth sign, and thinning of corpus callosum. A novel homozygous 36-bp insertion in PIBF1 (c.1181_1182ins36) was identified by exome sequencing as the likely cause of her condition. This is the second publication demonstrating the cause and effect relationship between PIBF1 and Joubert syndrome.