1. Canada's Michael Smith Genome Sciences Center; Vancouver British Columbia Canada
2. Department of Medical Genetics; University of British Columbia; Vancouver British Columbia Canada
3. Provincial Medical Genetics Programme; Children's and Women's Health Centre of British Columbia; Vancouver British Columbia Canada
4. Unidad de Genética y Diagnóstico Prenatal; Hospital Universitario y Politécnico La Fe. Valencia; Valencia Spain
5. CHU Sainte-Justine Research Center; Montréal Quebec Canada