BRAT1 Mutation: The First Reported Case of Chinese Origin and Review of the Literature

Abstract

Lethal neonatal rigidity and multifocal seizure syndrome (RMFSL) (OMIM#614498) is caused by homozygous or compound heterozygous mutation in the BRAT1 gene (OMIM#614506) on chromosome 7p22. We report a newborn female infant born to non-consanguineous Chinese parents who presented with hypertonia, dysmorphic features, progressive encephalopathy with refractory seizures, and worsening episodic apnea, leading to intubation and eventually death at 10 weeks of age. Whole exome sequencing revealed homozygous BRAT1 mutation, c.1395G>C (p.Thr465Thr), predicted to cause splice site disruption. Neuropathological assessment demonstrated microcephaly, severe neuronal loss, and background gliosis in the dorsal region of the putamen. Disruption of BRAT1 function in RMFSL has been proposed to cause dysfunction in the DNA damage response pathway and impair mitochondrial homeostasis. To our best knowledge this is the first reported case of Chinese origin. We review all published cases with BRAT1 mutation reported in the English literature and known BRAT1 functions which provide insight into the pathophysiology of the disease.