The muscular dystrophies are inherited progressive disorders which cause
breakdown of muscle fibres. In the early days of muscular dystrophy
research four main types of muscular dystrophy were known - Duchenne,
facioscapulohumeral, myotonic and a final group which was given the name
of limb-girdle muscular dystrophy (LGD).
The main features of the limb-girdle type were that the muscles of the upper
or "proximal" parts of the limbs were mainly involved, the muscles of the face
were spared and the symptoms of the weakness were usually first noted in
late childhood, adolescence or adult life (thus differing from the Duchenne
type). Both males and females might be affected and their brothers or sisters
were much more often affected than their parents or children.
It is now known that a number of conditions with different causes and
different genetic implications may present with symptoms similar to this.
It is evident, therefore, that the term "limb-girdle muscular dystrophy"
may be applied loosely to many quite different disorders. This is
important because these disorders differ in their rate of progression, outcome
and especially in their mode of inheritance so that misleading genetic advice
may be given if a more precise diagnosis is not made. Some doctors now
consider that the name "limb-girdle muscular dystrophy" should no longer be
used at all, and it seems clear that people who have been given this
diagnosis should receive up to date advice about the particular type
that is affecting them or members of their family.