CACNA1A and cerebellar ataxia: Data pooling with centralized analyses or re-analyses, as in the European Integrated Project on Spinocerebellar Ataxias (EUROSCA) (www.eurosca.org), the study of individuals at risk for SCA1, SCA2, SCA3 and SCA6 (RISCA) [15] and the ENIGMA project (http://enigma.ini.usc.edu/ongoing/enigma-ataxia).