Kaplan F, Kokotsis G, DeBraekeleer M, Morgan K, Scriver C R
DeBelle Laboratory for Biochemical Genetics, McGill University-Montreal Children's Hospital Research Institute, Quebec, Canada.
Am J Hum Genet. 1990 Jan;46(1):126-32.
beta-Thalassemia minor occurs at approximately 1% frequency in French-Canadians--in families residing in Portneuf County (population approximately 40,000) of Quebec province. We found eight different RFLP haplotypes at the beta-globin gene cluster in 37 normal persons and in 12 beta-thalassemia heterozygotes from six families. beta-Thalassemia genes in these families associated with two haplotypes only: Mediterranean I and Mediterranean II. There were two different beta-thalassemia mutations segregating in the Portneuf population: an RNA processing mutation (beta(+)IVS-1,nt110) on haplotype I (five families) and a point mutation leading to chain termination (beta(0) nonsense codon 39) on haplotype II (one family). The distribution of 5' haplotypes on normal beta A Portneuf chromosomes compared with other European populations was most similar to that in British subjects (data for French subjects have not yet been reported). Genealogical reconstructions traced the ancestry of carrier couples to settlers emigrating from several different regions of France to New France in the 17th century. These findings indicate genetic diversity of a greater degree among French-Canadians than recognized heretofore.
轻度β地中海贫血在法裔加拿大人中的发生率约为1%，在魁北克省波特讷夫县（人口约4万）的家庭中亦是如此。我们在37名正常人以及来自6个家庭的12名β地中海贫血杂合子的β珠蛋白基因簇中发现了8种不同的限制性片段长度多态性（RFLP）单倍型。这些家庭中的β地中海贫血基因仅与两种单倍型相关：地中海I型和地中海II型。在波特讷夫人群中分离出两种不同的β地中海贫血突变：单倍型I（5个家庭）上的一种RNA加工突变（β(+)IVS-1，nt110）和单倍型II（1个家庭）上导致链终止的点突变（β(0)无义密码子39）。与其他欧洲人群相比，正常βA波特讷夫染色体上5'单倍型的分布与英国受试者的最为相似（法国受试者的数据尚未报告）。系谱重建将携带基因的夫妇的祖先追溯到17世纪从法国几个不同地区移民到新法兰西的定居者。这些发现表明，法裔加拿大人中的遗传多样性程度比迄今所认识到的更高。
