Evaluating Dysfunction in Fever-Induced Paroxysmal Weakness and Encephalopathy.

Area of Science:

• Genetics and Neurology
• Molecular Biology

Background:

• ATP1A3 gene variants are associated with neurological disorders.
• A distinct phenotype, fever-induced paroxysmal weakness and encephalopathy (FIPWE) or relapsing encephalopathy with cerebellar ataxia (RECA), is linked to Arg756 variants in ATP1A3.
• Fewer than 20 cases of FIPWE/RECA have been reported, necessitating further clinical description.

Observation:

• A 3-year-old male presented with recurrent episodes of hypotonia, gait loss, mutism, and dystonia triggered by fever.
• Electrophysiological studies, including electroencephalography (EEG) and nerve conduction studies (NCS), showed no abnormalities during neurological decompensation.
• Genetic analysis revealed a heterozygous p.Arg756Cys mutation in the ATP1A3 gene.

Findings:

• The patient's clinical presentation and genetic findings are consistent with FIPWE/RECA.
• Normal EEG and NCS results during febrile episodes are notable in this ATP1A3-related disorder.
• This case expands the understanding of FIPWE/RECA clinical features and diagnostic considerations.

Implications:

• Normal electrophysiological findings do not exclude FIPWE/RECA.
• Early suspicion of FIPWE/RECA is crucial for timely diagnosis and management.
• Further research into ATP1A3 variants at Arg756 is needed to fully elucidate the phenotype.