The Autosomal Dominant Facioscapuloperoneal Muscular Dystrophy with 4q35 Chromosomal Deletion in Two Russian Families

We give the description of the pattern of muscle affections in two autosomal dominant 4q35-linked facioscapuloperoneal muscular dystrophy (FSPMD) families in which the patients were re-examined by V.K. in 24 -28 and 35 -37 years after their first examination. The disease started with initial involvement of facial and shoulder girdle muscles and in some time later of the peroneal group (anterior tibial) of muscles became involved. However, in two probands the dystrophic process gradually extended to the thighs (posterior group of muscles, namely), pelvic girdle (gluteus maximus muscles, namely) and the upper arm (biceps brachii muscles were slightly affected) and in three their relatives with clinical facioscapuloperoneal (FSP) phenotype the severe involvement of some posterior thigh muscles during MRI study was revealed. In this connection, the term "facioscapulolimb muscular dystrophy, type 2 (FSLD2), a descending type with a "jump" with initial FSP phenotype" would be more correct instead of the name facioscapuloperoneal muscular dystrophy. The FSP phenotype constitutes merely a stage in the development of FSLD2. The CT and MRI pattern of muscle involvement does not fully correlate with clinical pattern of muscle affection. We suppose that classical AD FSPMD is an independent clinical form which is different from the classical FSHD although both of them are connected with 4q35 chromosomal deletion.