%0 Journal Article %A M Pembrey %A S J Fennell %A J van den Berghe %A M Fitchett %A D Summers %A L Butler %A C Clarke %A M Griffiths %A E Thompson %A M Super %T The association of Angelman's syndrome with deletions within 15q11-13. %D 1989 %R 10.1136/jmg.26.2.73 %J Journal of Medical Genetics %P 73-77 %V 26 %N 2 %X The inheritance of Angelman's syndrome, a disorder characterised by mental retardation, epilepsy, ataxia, and a happy disposition, is debated because affected sibs occur less frequently than expected with autosomal recessive inheritance. After discovering two unrelated patients with a small deletion of the proximal long arm of chromosome 15, 10 further patients with Angelman's syndrome were reassessed. Five had apparently normal karyotypes, four had a deletion within 15q11-13, and one had a pericentric inversion, inv(15)(p11q13) involving the same chromosomal region. In the latter case, the healthy mother had the same pericentric inversion, indicating that the patient also had a submicroscopic mutation on his other chromosome 15. These data map the Angelman locus to 15q11-13 and suggest that de novo visible deletions (associated with a low recurrence risk) and autosomal recessively inherited cases combine to give an overall sib recurrence risk of less than 25%. %U https://jmg.bmj.com/content/jmedgenet/26/2/73.full.pdf