[1] Case Western Reserve Univ, Dept Genet, Cleveland, OH 44106 USA
[2] Univ Geneva, Sch Med, Div Med Genet, CH-1211 Geneva, Switzerland
[3] Cantonal Hosp, Geneva, Switzerland
[4] John F Kennedy Inst, Danish Ctr Human Genome Res, DK-2600 Glostrup, Denmark