Abstract
In 14 patients with non-congenital myotonic dystrophy included 8 males and 6 females died at our hospital during the last three years, we investigated their ages at onset and death, duration of the disease, causes of the death, complications, and CTG repeat expansion assessed by direct genotype analysis of white blood cell DNA. The mean age at onset, age at death, disease duration, and CTG repeat expansion were 28.5 years (SD±11.3; range, 14-45 years), 55.9 years (SD±6.0; range, 46-63 years), 27.4 years (SD±10.7; range, 16-49 years), and 6.16 kb (SD±2.73; range, 3.3-11.7 kb), respectively. There were no sex differences in those investigations.
A strong negative correlation between the age at onset and desease duration was found (r=-0.855, p<0.0001). Seven (50%) patients died from respiratory failure and/or pneumonia, 5 (35.7%) from heart failure and/or arrhythmia, 1 (7.1%) from malignancy, and 1 patient (7.1%) died suddenly. As the complications, all patients had abnormalities of electrocardiogram. Diabetes mellitus, cholelithiasis or cataracta was recognized in 7 patients, respectively, myoma uteri or cerebral infarction in 3, respectively, and malignancy in 2.
From our results, it is considered that the death at mid-fifties is caused by multiple factors and functional failures of the generalized organs, which reveal CTG repeat expansion in patients with non-congenital myotonic dystrophy at the present time. Therefore, it is necessary to examine functional failures of the generalized organs in detail to increase the mean age death.
