Centre for the Research and Rehabilitation of Hereditary Ataxias, 80100, Holguín, Cuba.
Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 91540-070, Brazil.
Cerebellum. 2020 Jun;19(3):446-458. doi: 10.1007/s12311-020-01109-7.
Spinocerebellar ataxias (SCAs) comprise a heterogeneous group of autosomal dominant disorders. The relative frequency of the different SCA subtypes varies broadly among different geographical and ethnic groups as result of genetic drifts. This review aims to provide an update regarding SCA founders in the American continents and the Caribbean as well as to discuss characteristics of these populations. Clusters of SCAs were detected in Eastern regions of Cuba for SCA2, in South Brazil for SCA3/MJD, and in Southeast regions of Mexico for SCA7. Prevalence rates were obtained and reached 154 (municipality of Báguano, Cuba), 166 (General Câmara, Brazil), and 423 (Tlaltetela, Mexico) patients/100,000 for SCA2, SCA3/MJD, and SCA7, respectively. In contrast, the scattered families with spinocerebellar ataxia type 10 (SCA10) reported all over North and South Americas have been associated to a common Native American ancestry that may have risen in East Asia and migrated to Americas 10,000 to 20,000 years ago. The comprehensive review showed that for each of these SCAs corresponded at least the development of one study group with a large production of scientific evidence often generalizable to all carriers of these conditions. Clusters of SCA populations in the American continents and the Caribbean provide unusual opportunity to gain insights into clinical and genetic characteristics of these disorders. Furthermore, the presence of large populations of patients living close to study centers can favor the development of meaningful clinical trials, which will impact on therapies and on quality of life of SCA carriers worldwide.
脊髓小脑共济失调（SCA）是一组常染色体显性遗传病。由于遗传漂变，不同 SCA 亚型在不同地理和种族群体中的相对频率差异很大。本综述旨在提供有关美洲大陆和加勒比地区 SCA 创始人的最新信息，并讨论这些人群的特征。在古巴东部地区发现了 SCA2 的聚集病例，在南巴西发现了 SCA3/MJD 的聚集病例，在墨西哥东南部地区发现了 SCA7 的聚集病例。获得了患病率，达到了 154（古巴的巴瓜诺市）、166（巴西的根廷卡马拉）和 423（墨西哥的特拉拉泰莱）每 10 万人中有 SCA2、SCA3/MJD 和 SCA7 患者。相比之下，在整个南北美洲发现的散发性脊髓小脑共济失调 10 型（SCA10）家族与一个共同的美洲原住民血统有关，该血统可能起源于东亚，并在 10000 至 20000 年前迁移到美洲。全面的综述表明，对于每一种 SCA，至少有一个研究小组开展了研究，产生了大量的科学证据，这些证据通常可以推广到所有患有这些疾病的患者。美洲大陆和加勒比地区的 SCA 人群聚集为深入了解这些疾病的临床和遗传特征提供了难得的机会。此外，大量患者居住在靠近研究中心的地方，可以为有意义的临床试验的开展提供有利条件，这将对全球 SCA 患者的治疗和生活质量产生影响。
