Recurrent Acute Liver Failure in a Bahraini Child With a Novel Mutation of Spinocerebellar Ataxia-21.

Acute liver failure (ALF) in children is a rare life-threatening condition. ALF is caused by different etiologies. The most common causes are drug-induced liver injury, infections, and metabolic diseases. Other rare causes of ALF are genetic disorders including spinocerebellar ataxia-21 (SCAR21). Herein, we describe the first Bahraini child who was diagnosed with a novel homozygous mutation in the SCYL1 gene. He was admitted to the hospital twice by the age of two and five years due to acute hepatic failure triggered by a febrile illness. Drug-induced, infectious causes, and metabolic diseases were excluded. The liver function then gradually recovered. The patient had delayed gross motor development as he started to walk at 20 months of age. After the first episode of ALF, he had progressive difficulty in walking leading to frequent falls and ending with a complete inability to walk. A whole-exome sequencing (WES) test revealed that the patient has previously unreported autosomal recessive pathogenic non-sense variation c.895A>T (p.Lys299Ter) in exon 7 of the SCYL1 gene in a homozygous status. It is confirmed that the pathogenicity of this variant in the SCYL1 gene was associated with SCAR21 disease.