Clinical and molecular characteristics of tectonic (TCTN1) gene-related Joubert syndrome in a Saudi boy.

Joubert syndrome (OMIM:609863) is a hereditary disorder characterized by hypotonia, developmental delay, and a distinctive cerebellar and brain stem malformation known as the molar tooth sign. Variants in tectonic genes TCTN1-3 have been described in a few patients with Joubert syndrome. Furthermore, Joubert syndrome attributed to variants in the TCTN1 (NM_001082538.2) gene has been only described in two reports. This report expands the clinical variability and molecular characterization of an emerging novel causative gene for Joubert syndrome in a Saudi boy born to non-consanguineous marriage with a c.1418del p.(Pro473Leufs*42) and c.800A > G p.(Tyr267Cys) representing a novel compound heterozygous variant of the TCTN1 gene identified by whole-exome sequencing and confirmed by Sanger sequencing. This is the first report of compound heterozygous Joubert syndrome type 13 from Saudi Arabia.

Neuroblastoma amplified sequence gene mutation: A rare cause of recurrent liver failure in children.

Neuroblastoma amplified sequence (NBAS) gene mutation or infantile liver failure syndrome type 2 (ILFS type 2) is an extremely rare disease characterized by episodic liver failure precipitated by intercurrent febrile illness, and liver function recovering completely. Here, we report a 4-year-old girl with recurrent hepatitis. A diagnosis of ILFS type 2 was made based on NBAS mutation gene found by whole-exome sequencing. Our case provides a new insight toward considering NBAS mutation as a part of the differential diagnoses of any infant presenting with recurrent liver failure or hepatitis. We recommend sequencing NBAS in cases of recurrent hepatitis in infancy of unknown cause, especially in individuals with fever-associated hepatic dysfunction.