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Abstract
PURPOSE: Previous studies have shown that persons with retinitis pigmentosa and Usher's syndrome have lower blood levels of long-chain polyunsaturated fatty acids (PUFAs). In this study, the fatty acid composition of phospholipids from plasma and red blood cells (RBCs) was compared in persons with Usher's syndrome type I; Usher's syndrome type II; or no retinal disease (control subjects). METHODS: Blood was drawn from fasting volunteers and separated into plasma and RBCs by centrifugation. Lipids were extracted and phospholipids were obtained by thin-layer chromatography. Fatty acid methyl esters were prepared and analyzed by gas-liquid chromatography. RESULTS: There were no differences in plasma or RBC phospholipid fatty acid composition between control subjects (n = 54) and persons with Usher's syndrome type II (n = 20). However, all 20- and 22-carbon PUFA levels from RBCs of persons with Usher's syndrome type I were lower than those from control subjects and persons with Usher's Syndrome type II. Likewise, plasma levels of 20:3n-6, 20: 5n-3, and 22:6n-3 were lower in Usher's syndrome type I compared with the control group. In contrast, plasma levels of 18:1n-9 and RBC levels of 16:0 and 18:1n-9 were higher in the group with Usher's syndrome type I. CONCLUSIONS: Plasma and RBCs from Usher's syndrome type I, but not type II, have lower levels of long-chain PUFAs than plasma and RBCs from control subjects.