Congenital means ‘from birth’, and in CMDs, the initial symptoms are present at birth or in the first few months of life. They are a very varied group of conditions. Much effort has gone into defining the subtypes and identifying the genes responsible for these specific forms of CMD.
UCMD is a form of congenital muscular dystrophy with specific features:
- the joints of the hands and feet have ‘bendiness’ or ‘hyperlaxity’, while the elbows, hips and knee joints have ‘contractures’ or ‘tightness’
- the spine can have a curvature (scoliosis) or rigidity (stiffness)
- respiratory muscle weakness and insufficiency develops over time, with the need for night-time non-invasive ventilation by the mid-teenage years.
There are three genes responsible for UCMD: they are called COL6A1, COL6A2 and COL6A3, and they carry the genetic blueprint that is used to produce a protein called collagen VI.