QUANTITATIVE ELISA FOR PLATELET M-CALPAIN - A PHENOTYPIC INDEX FOR DETECTION OF CARRIERS OF DUCHENNE MUSCULAR-DYSTROPHY

In order to measure the amount of m-calpain in platelets from Duchenne muscular dystrophy (DMD) patients, carriers and controls, an enzyme l inked immunosorbent assay (ELISA) has been developed using polyclonal antibodies raised against m-calpain (Calcium dependent neutral proteas e), purified from human placenta. Compared to controls a nine-fold inc rease in the level of m-calpain was observed in all 25 DMD patients an d eight obligate carrier mothers studied. Serum creatine kinase (SCK) values of four of these obligate carriers were found to be overlapping with that of normal values, limiting its usefulness. Since calpain le vels were found to be raised in all DMD patients and obligate carriers , the estimation of calpain in all female relatives of the ones affect ed with DMD (with or without raised serum CK) would prove a facile ind ex. Population screening for carrier females using this cost and labou r effective index may help in assessing the carrier status and counsel ling the at risk families. (C) 1998 Published by Elsevier Science B.V.