Centre for Environmental and Preventive Medicine, Wolfson Institute of Preventive Medicine, London, UK.
Am J Med Genet A. 2012 May;158A(5):1145-50. doi: 10.1002/ajmg.a.35337. Epub 2012 Apr 11.
This study describes the cytological and epidemiological findings in 985 trisomy 13 and 2512 trisomy 18 compared with 10,255 trisomy 21 diagnoses between 2004 and 2009 included in the National Down Syndrome Cytogenetic Register of England and Wales. The frequency of occurrence, proportions diagnosed prenatally, sex ratios, mean maternal age, and proportions of mothers with recurrences were analyzed. Ninety-seven, 98%, and 92% were free karyotypes for trisomy 21, 18, and 13, respectively; 3% of 21, 1% of 18, and 8% of trisomy 13 were translocations; and under 1% of trisomies 21 and 18 were double or triple aneuploids. Overall 1% of each trisomy had mosaicism, but 48% of the trisomy 21 double aneuploids, and 10% of trisomy 18 multiple aneuploids had mosaicism. The proportion of livebirths was 40% of trisomy 21, 11% of 18, and 13% of 13, respectively. Free trisomies 21 and 13 had an excess of males, and 18 had an excess of females, as did mosaic free trisomies 21 and 18. Mean maternal ages were 35.9 years in trisomy 21, 36.4 years in 18, and 34.6 years in 13. During the 6 years of data collection 1% of the mothers had recurrences, most recurrent trisomy 21 or 18 were identical translocations, but hetero-trisomic recurrences included 21 and 18, and 21 and 13. There are significant differences between the trisomic karyotypes and attributes, possibly related to their variable origins. Notable are the relative excess of trisomy 13 translocations, mosaicism in cases with multiple aneuploidy, and the types of homo- and hetero-recurrences.
本研究描述了 2004 年至 2009 年期间纳入英格兰和威尔士国家唐氏综合征细胞遗传学登记处的 985 例三体 13 和 2512 例三体 18 与 10255 例三体 21 病例的细胞遗传学和流行病学发现。分析了发生率、产前诊断比例、性别比例、母亲平均年龄和复发母亲比例。三体 21、18 和 13 的游离核型分别为 97%、98%和 92%；21 三体的 3%、18 三体的 1%和 13 三体的 8%为易位；21 三体和 18 三体的异常染色体少于 1%。总体而言，每种三体的嵌合体比例为 1%，但 21 三体的双非整倍体中为 48%，18 三体的多非整倍体中为 10%。活产比例分别为 21 三体的 40%、18 三体的 11%和 13 三体的 13%。游离三体 21 和 13 男性比例过高，18 三体女性比例过高，游离三体 21 和 18 嵌合体也是如此。21 三体的母亲平均年龄为 35.9 岁，18 三体为 36.4 岁，13 三体为 34.6 岁。在 6 年的数据收集期间，有 1%的母亲出现复发，大多数复发的 21 三体或 18 三体为相同的易位，但异三体的复发包括 21 三体和 18 三体，以及 21 三体和 13 三体。不同的三体核型和特征之间存在显著差异，这可能与其可变起源有关。值得注意的是，13 三体易位的相对过剩，多非整倍体病例中的嵌合体，以及同型和异型复发的类型。
