Abetalipoproteinemia (Neurologic Form)

Abetalipoproteinemia is an autosomal recessive disorder caused by mutations in the MTTP gene, resulting in defective assembly and secretion of apolipoprotein B-containing lipoproteins. The neurologic phenotype arises primarily from chronic vitamin E deficiency, leading to progressive sensory neuropathy, ataxia, and dysarthria. Early manifestations may include steatorrhea, failure to thrive, and acanthocytosis. Diagnosis is confirmed by serum lipid profiling, electrophysiologic studies, and genetic testing. Management focuses on dietary modification and high-dose fat-soluble vitamin supplementation, particularly vitamin E, which can prevent or slow neurological deterioration when initiated early.