of the deficiency of P-dystroglycan, since P-dystroglycan is believed to be crucial for linking dystrophin and a-dystroglycan to the sarcolemma. Although it is quite unlikely that the normal molecular organization of the complex is maintained without P-dystroglycan, the present finding suggests that there may be another dystrophin-anchoring site, possibly in the sarcoglycan complex. Also, there might be a direct interaction between a-dystroglycan and the sarcoglycan complex for maintaining the membrane organization of a-dystroglycan without P-dystroglycan. These interesting possibilities should be studied by further biochemical experiments.
A man, 23 years of age, had a typical erythema infectiosum, complicated by a severe bilateral brachial plexus neuritis. Motor function recovered slowly and only partially after 6 months. An infection by human parvovirus B19 was demonstrated, with strongly positive and gradually declining I@ antibodies and viral DNA detectable in serum for more than 3 months. There was also clear evidence of a recent infection by cytomegalovirus. The interaction between these two viruses could be responsible for this rare and severe complication of common infections in this patient.