[1] Univ Leeds, St Jamess Univ Hosp, Dept Clin Genet, Leeds LS9 7TF, W Yorkshire, England
[2] Univ Leeds, St Jamess Univ Hosp, Mol Med Unit, Leeds LS9 7TF, W Yorkshire, England
[3] Hull Royal Infirm, Dept Paediat, Kingston Upon Hull HU3 2JZ, N Humberside, England
[4] Hull Royal Infirm, Dept Ophthalmol, Kingston Upon Hull HU3 2JZ, N Humberside, England
[5] Hull Royal Infirm, Dept Neuroradiol, Kingston Upon Hull HU3 2JZ, N Humberside, England
[6] Leeds Gen Infirm, Dept Paediat Neuro, Leeds, W Yorkshire, England
[7] Hop St Vincent de Paul, Serv Virol, F-75674 Paris, France
[8] Great Ormond St Hosp Children, Dept Ophthalmol, London WC1N 3JH, England
[9] Great Ormond St Hosp Children, Dept Clin Genet, Inst Child Hlth, London WC1N 3JH, England