Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil.
Genet Mol Biol. 2011 Jan;34(1):45-8. doi: 10.1590/S1415-47572011000100009. Epub 2011 Mar 1.
Infantile GM1 gangliosidosis is caused by the absence or reduction of lysosomal beta-galactosidase activity. Studies conducted in Brazil have indicated that it is one of the most frequent lysosomal storage disorders in the southern part of the country. To assess the incidence of this disorder, 390 blood donors were tested for the presence of two common mutations (1622-1627insG and R59H) in the GLB1 gene. Another group, consisting of 26 GM1 patients, and the blood donors were tested for the presence of two polymorphisms (R521C and S532G), in an attempt to elucidate whether there is a founder effect. The frequencies of the R59H and 1622-1627insG mutations among the GM1 patients studied were 19.2% and 38.5%, respectively. The frequency of polymorphism S532G was 16.7%, whereas R521C was not found in the patients. The overall frequency of either R59H or 1622-1627insG was 57.7% of the disease-causing alleles. This epidemiological study suggested a carrier frequency of 1:58. Seven different haplotypes were found. The 1622-1627insG mutation was not found to be linked to any polymorphism, whereas linkage disequilibrium was found for haplotype 2 (R59H, S532G) (p < 0.001). These data confirm the high incidence of GM1 gangliosidosis and the high frequency of two common mutations in southern Brazil.
婴儿型神经节苷脂贮积症是由溶酶体β-半乳糖苷酶活性的缺失或减少引起的。巴西的研究表明，它是该国南部最常见的溶酶体贮积症之一。为了评估这种疾病的发病率，对 390 名献血者进行了 GLB1 基因中两个常见突变（1622-1627insG 和 R59H）的存在测试。另一组由 26 名 GM1 患者和献血者组成，测试了两个多态性（R521C 和 S532G）的存在，试图阐明是否存在创始效应。在所研究的 GM1 患者中，R59H 和 1622-1627insG 突变的频率分别为 19.2%和 38.5%。多态性 S532G 的频率为 16.7%，而患者中未发现 R521C。R59H 或 1622-1627insG 的总频率为致病等位基因的 57.7%。这项流行病学研究表明，携带者的频率为 1:58。发现了 7 种不同的单倍型。1622-1627insG 突变与任何多态性无关，而 2 号单倍型（R59H、S532G）存在连锁不平衡（p<0.001）。这些数据证实了 GM1 神经节苷脂贮积症在巴西南部的高发病率和两种常见突变的高频率。
