1. Human Genetics David Geffen School of Medicine University of California Los Angeles Los Angeles CA 90095 USA
2. Biostatistics Fielding School of Public Health University of California Los Angeles Los Angeles CA 90095 USA
3. Department of Experimental, Diagnostic and Specialty Medicine University of Bologna Bologna 40126 Italy
4. Interdepartmental Center ‘L. Galvani’ University of Bologna Bologna 40126 Italy
5. CNR Applied Biomedical Research Center S. Orsola‐Malpighi Polyclinic Bologna 40138 Italy
6. Personal Genomics S.r.l. Verona 37134 Italy
7. Center of Research and Biomedical Technology Istituto Auxologico Italiano IRCCS Via Zucchi 18 Cusano Milanino 20095 Milan Italy
8. Department of Biological, Geological and Environmental Sciences University of Bologna Bologna 40126 Italy
9. Department of Neurology and Department of Pathology and Laboratory Medicine David Geffen School of Medicine at UCLA Los Angeles CA 90095 USA
10. IRCCS Institute of Neurological Sciences of Bologna 40139 Bologna Italy