[P1-178] A Case of Infantile Refsum Disease Associated with Hypobetalipoproteinemia
Infantile Refsum disease (IRD) is a rare perixisome biogenesis disorder with wide range of clinical severity. We experienced a mild form of IRD who had been followed as a symptomatic hypobetalipoproteinemia resembling with abetalipoproteinemia. Case: 31 year-of age, male. His parents were second cousins. Development during infancy was normal. He could walk alone but unsteadily from the age of 17 months. He could not speak until the age of two years, when hearing loss was noticed. Growth was within normal limits.He had no history of persistent diarrhea or loose stool suggesting fat malabsorption. At 6 year-of-age, he was diagnosed as having hypobetalipoproteinemia with spinocrebellar degeneration, peripheral neuropathy, retinitis pigmentosa, mild mental retardation (IQ70), and sensorineural hearing loss. Although his vitamin E level was low and normalized after oral supplementation, his clinical symptoms were worsen very slowly. He has been using wheelchair since high school age. MRI showed slowly progressive cerebellar atrophy. Marked lymphedema of legs developed in the second decade. At 30 year-of-age, elevated levels of very long chain fatty acids and phytanic acid and decreased plasmalogen were detected in his plasma. Genetic analysis revealed a homozygous mutation of Q67R in PEX10. His parents had the heterozygous mutations.
Although the pathogenesis of hypobetalipoproteinemia in this case is unknown, plasmalogen deficiency, which affects lipid metabolism, could play a role for it. It should be cautious to differentiate symptomatic hypobetalipoproteinemia with IRD.
Although the pathogenesis of hypobetalipoproteinemia in this case is unknown, plasmalogen deficiency, which affects lipid metabolism, could play a role for it. It should be cautious to differentiate symptomatic hypobetalipoproteinemia with IRD.