Research Highlights

Rare syndrome point to role of gene in brain development

Published online 8 October 2013

Sara Osman

A new syndrome defined by a set of severe clinical manifestations including decreased brain size, visual impairment, kidneys and urinary tract dysfunctions, and insufficiency in the function of the pituitary gland, which secretes a group of hormones that regulate several body functions, has been reported in the offspring of closely related parents in Saudi Arabia.

By scouring the genomes of the affected children for homozygous SNPs — identical mutations that occur on both alleles — the international team of researchers involving researchers from King Saud bin Abdulaziz University for Health Sciences and King Faisal Specialist Hospital and Research Center, Saudi Arabia, identified a mutation in the ARNT2 gene, and report their finding in the journal Brain.

ARNT2 is a protein that belongs to a class of transcription factors that control neural differentiation during the brain's development. The mutation resulted in an almost complete absence of ARNT2 in the cells of the patients.

The researchers went on to profile the expression of ARNT2 in different parts of the human brain during development. The severity of the clinical manifestations of this rare syndrome highlights the indispensable role played by ARNT2 in the development of the brain, as well as the kidneys and urinary tract.


  1. Webb, E. et al. ARNT2mutation causes hypopituitarism post-natal microcephaly, visual and renal anomalies. Brain 136: 3096-3105 (2013) doi:10.1093/brain/awt218