Abstract

Previous studies have shown that in vitro muscle ribosomal protein synthesis (RPS) by monomeric ribosomes (MR) and total polyribosomes (TPR) and collagen synthesis (CS) are significantly increased (P less than 0.01) in 47 known carriers of Duchenne muscular dystrophy as compared to 60 age-matched controls. However, there was considerable overlap of the distribution of controls and carriers, particularly for monomeric ribosomal protein synthesis and collagen synthesis. To improve detection of carriers we used discriminant analysis utilizing logs of each measurement as superior to a univariate or bivariate scheme. This study considered four groups: proven carriers (30) (group 1), presumptive carriers (female relatives of Duchenne patients with high serum creatine kinase (CK) levels) (32) (group 2), controls greater than or equal to 20 years old (42) (group 3) and controls less than 20 years (36) (group 4). Comparison of groups, Misclassification (%), (see chart). These results suggest that discriminant analysis reduces the misclassification rates as compared with univariate or bivariate analysis and confirm the superiority of RPS measurements as a carrier test for Duchenne muscular dystrophy.