Concentration and Fatty Acid Composition of Serum Lipids in Myotonia Dystrophica

Abstract

Serum lipids of 9 patients with myotonia dystrophica and a myotonia congenita were examined. The contents of serum lipids examined in this study were desmosterol, total cholesterol, triglycerides and free fatty acids (F.F.A.). The fatty acid compositions of cholesterol ester, triglycerides, F.F.A. and phospholipid were also measured. All four lipids were significantly elevated in myotonia dystrophica. Desmosterol was abnormally increased in 8 out of 9 patients. All four lipids were within normal range in the myotonia congenita. In myotonia dystrophica, fatty acid compositions were significantly altered in several fractions of F.F.A. and phospholipid; decreases of C14:0 and C16:1 and an increase of C18:1 of F.F.A., a decrease of C16:1 and an increase of C18:0 of phospholipid were all statistically significant. Several significant changes were also observed in myotonia congenita in the fatty acid composition. The changes commonly found in both myotonia dystrophica and myotonia congenita were the increase of C18:1 of F.F.A the increase of C18:0 and the decrease of C16:1 of phospholipid. The authors propose a theory that the degenerative changes of myotonia dystrophica might be attributed to abnormal lipid metabolism, particularly that of desmosterol-cholesterol conversion and that the abnormalities of fatty acid metabolism might contribute to the myotonic symptoms in both disease entities. 1 Summary of this study was reported at the 12th annual meeting of the Japanese Society of Neurology, 3-4 April, 1971, Tokyo, Japan