1. Research Center for Genetic Medicine, Children's National Medical Center; Washington DC USA
2. Department of Integrative Systems Biology; The George Washington University School of Medicine and Health Sciences; Washington DC USA
3. Department of Medical Genetics; Institute of Mother and Child; Warsaw Poland
4. Department of Neurology; Medical University of Warsaw; Warsaw Poland
5. Neuromuscular Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences; Warsaw Poland
6. National Institute of Neurological Disorders and Stroke/NIH, Porter Neuroscience Research Center; Bethesda Maryland USA
7. Department of Medical Genetics; The Children's Memorial Health Institute; Warsaw Poland