[1] Hammersmith Hosp, ICSM, Dubowitz Neuromusc Ctr, London, England
[2] Univ Oxford, Dept Human Anat & Genet, Oxford, England
[3] Univ Cagliari, Dept Cytomorphol, Cagliari, Italy
[4] Hpital Raymond Poincar, Garches, France
[5] Pitie Salpetriere, INSERM, U523, Paris, France
[6] Univ Essen Gesamthsch, Dept Paediat, Essen, Germany
[7] Robert Jones & Agnes Hunt Orthopaed Hosp, Dept Histopathol, Oswestry SY10 7AG, Shrops, England