Increased frequency of gray zone-premutated fraxa alleles in brazilian mentally impaired boys - Haddad, Luciana Amaral; Aguiar, M J B; Costa, S. S.; Mingroni Netto, Regina Celia; Vianna-Morgante, Angela M; Pena, Sérgio D. J. (International Workshop on the Fragile X and X-linked Mental Retardation, 1997)