CLINICAL VARIABILITY OF FACIOSCAPULOHUMERAL MUSCULAR-DYSTROPHY IN RUSSIA

One hundred forty-two patients (66 men and 76 women) from 20 autosomal -dominant pedigrees and 3 families including 5 ''sporadic'' cases were examined. A great similarity of clinical manifestations among those a ffected was noted. Clinical variability of phenotypes reflecting vario us phases of the disease and different expressions of the mutant gene were always within the limits of the identical final phenotype of the disease, namely the facio-scapulo-humero-peroneal-femoro (posterior gr oup of the muscles)-gluteal (gluteus maximus). Thus, the clinically an d genetically homogeneous group of patients with autosomal-dominant de scending with a ''jump'' form of facioscapulohumeral dystrophy (FSHD), called facioscapuloperoneal dystrophy (FSPD), was examined. Among the observed cases we did not come across any having the autosomal-domina nt gradually descending form of FSHD, called facioscapulolimb dystroph y (FSLD), in which the pelvic and proximal lower limb muscles get weak earlier than in the peroneal group (anterior tibial) muscles. We coul d not reveal the ''pure'' facioscapulohumeral phenotype of muscle weak ness in 142 examined patients. A ''pure'' FSHD does not exist as a nos ological entity. If represents only the syndrome which characterizes t he initial phase of FSLD, but not of the FSPD. It is quite probable th at FSPD and FSLD which may be differentiated clinically are two differ ent diseases connected with the mutation of allelic or even different genes. Linkage studies in FSPD and FSLD mapping genes would confirm th is data. (C) 1995 John Wiley and Sons, Inc.