Clinical and genetic analysis of a family with familiar acute necrotizing encephalopathy due to mutation in the RANBP2 gene

Abstract

Objective To analyze the clinical manifestations of familial acute necrotizing encephalopathy (ANE) and to improve the recognition of this disease. Methods The clinical data of a 25-month-old girl with familial and recurrent ANE with evidence of mutation in the RANBP2 gene were collected and analyzed, and the gene examination of their family members was performed. Results A previously healthy girl experienced recurrent ANE episodes at the ages of 8 months, 18 months and 25 months, respectively.At each beginning of each episodes the patient presented with lethargy and tremor of limbs following febrile illness of 3-4 days, even developed coma and convulsions in the last time.Brain magnetic resonance imaging showed bilateral and high T2 signal changes in thalamus, cerebellum and hippocampus.Abnormal signals also appeared in the brainstem, claustrum, corpus scallosum and cortex (temporal, parietal and cingulate) also appeared abnormal signals.Spinal MRI showed spinal cord involvement.The girl recovered after her first episode; she could speak but could not walk steadily after the second time; after the third episode, although she regained consciousness from coma, she could no longer speak or walk.The patient's sister died of encephalitis at the age of 18 months.Her paternal uncle had suffered from dysnoesia from meningitis at his 17 months of age.The patient and her grandmother, father, uncle and one of her aunts harbored a mutation(c.1754C>T)in RANBP2 gene. Conclusions Familial ANE has typical clinical manifestations and characteristic MRI findings.The patient with recurrent history, especially with positive family history, should have the mutation in RANBP2 gene detected earlier in order to clarify the diagnosis of ANE. Key words: Acute necrotizing encephalopathy; Autosomal dominant; RANBP2 gene; Child