[Multiorgan abnormalities in myotonic dystrophy--correlation among endocrine disorders, central nervous system...

Myotonic dystrophy (DM) is a disease involving multiple organs. To elucidate the extent of severity of the affected organs in a given individual, we performed an investigation of the Ellsworth-Howard test (EH test), intelligence quotient (IQ), apnea index (AI), and expanded DNA fragment (EF) size in 10 patients with DM. The EF size analyzed by standard Southern blot procedures using EcoRI digested genomic DNA extracted from the peripheral white blood cells and probed with cDNA25. In the EH test, these patients were divided into two groups according to the results of their phosphaturic responses (delta P). Of these, 5 patients (Group I) showed a positive delta P, while remaining 5 patients (Group II) showed a negative one. In both Groups I and II, their urinary cyclic AMP responses were positive. Group II showed a significantly low value in IQ (p < 0.02) and a significantly high value in AI (p < 0.02) as compared with Group I. EF size in Group II was found significantly larger than in Group I (p < 0.01). A positive correlation between delta P and IQ (p < 0.1), a significant negative one between delta P and AI (p < 0.01), and a negative correlation between EF size and delta P (p < 0.2) were observed. IQ was negatively (p < 0.05), and AI was positively (p < 0.05) correlated with EF size, which were statistically significant. Our results suggest that the extent of disease severity of the central nervous system is almost the same as that of endocrine organs, and that EF size is correlated with disease severities in both affected organs.(ABSTRACT TRUNCATED AT 250 WORDS)