To the Editor: We read with interest the paper concerning capping in muscular dystrophy by Pickard et al. in the October 19, 1978, issue of the Journal. We have now investigated lymphocyte capping in nine patients with muscular dystrophy (seven Duchenne and two limb-girdle) and in nine known carriers of the disease. When compared with normal controls, no abnormality in the capping phenomenon was identified (per cent capping: 65.6±1.5 in controls, 64.3±2.1 in patients and 63.4±0.9 in carriers). We performed these experiments using technics that we have previously applied in several studies of capping in human B lymphocytes.1 By.