Hook E B, Schreinemachers D M, Willey A M, Cross P K
Am J Hum Genet. 1984 Mar;36(2):422-43.
Rates of structural chromosome abnormalities were analyzed in 24,951 fetuses studied prenatally in which there were no grounds to suspect an inherited abnormality. In about one in 200 prenatal cytogenetic diagnoses, an unexpected structural abnormality was found. The observed rate was 5.3 per 1,000, of which 1.7 per 1,000 were unbalanced and 3.6 per 1,000 balanced. The rate of inherited abnormalities was 3.1-3.7 per 1,000 (0.4-0.9 per 1,000 for unbalanced abnormalities and 2.6-2.8 per 1,000 for balanced abnormalities). The rate of mutants in this series was, by contrast, 1.6-2.2 per 1,000 (0.8-1.2 per 1,000 for unbalanced abnormalities and 0.8-1.0 per 1,000 for balanced abnormalities). The rate of balanced Robertsonian translocation carriers was 0.6 per 1,000 (about 0.25 per 1,000 for mutants and 0.35 per 1,000 for inherited abnormalities), and for other balanced abnormalities, 3.0 per 1,000 (about 0.6 per 1,000 for mutants and 2.4 per 1,000 for inherited abnormalities). The rates of unbalanced Robertsonian translocations was about 0.1 per 1,000, almost all of which were mutants. For supernumerary rearrangements, the rate was 0.9 per 1,000 (about 0.4 per 1,000 inherited and 0.5 per 1,000 mutant). The rates of all unbalanced (nonmosaic) inherited abnormalities (4.0-5.2 per 10,000) were intermediate between higher rates estimated in all conceptuses (9.1-15.8 per 10,000) and rates observed in newborns (1.5-2.5 per 10,000). This trend is probably attributable to fetal mortality associated with unbalanced rearrangements. The rates of balanced (nonmosaic) inherited abnormalities (26.0-28.0 per 10,000), however, were considerably higher than the rates in all conceptuses (13-16.7 per 10,000) or in all live births (12.2-16.0 per 10,000). The major difference was in the rate of inversions. The use of "banding" methods in the studies of amniocentesis but not in most of the live births or abortus studies probably contributes to at least some of these differences. One trend in parental age among the inherited abnormalities was noteworthy. Paternal age was elevated for inherited balanced reciprocal structural abnormalities of paternal origin but not of maternal origin. With regard to sex ratio, there was a greater proportion of females than males among the unbalanced rearrangements both inherited and mutant. There was no obvious sex difference among the balanced rearrangements.
对24951例产前检查的胎儿进行了结构染色体异常率分析，这些胎儿均无遗传异常的可疑迹象。在每200例产前细胞遗传学诊断中，约有1例会发现意外的结构异常。观察到的发生率为每1000例中有5.3例，其中每1000例中有1.7例为不平衡型，每1000例中有3.6例为平衡型。遗传异常的发生率为每1000例中有3.1 - 3.7例（不平衡型异常每1000例中有0.4 - 0.9例，平衡型异常每1000例中有2.6 - 2.8例）。相比之下，该系列中突变体的发生率为每1000例中有1.6 - 2.2例（不平衡型异常每1000例中有0.8 - 1.2例，平衡型异常每1000例中有0.8 - 1.0例）。平衡型罗伯逊易位携带者的发生率为每1000例中有0.6例（突变体约每1000例中有0.25例，遗传异常每1000例中有0.35例），其他平衡型异常的发生率为每1000例中有3.0例（突变体约每1000例中有0.6例，遗传异常每1000例中有2.4例）。不平衡型罗伯逊易位的发生率约为每1000例中有0.1例，几乎全部为突变体。对于额外的重排，发生率为每1000例中有0.9例（遗传的约每1000例中有0.4例，突变体每1000例中有0.5例）。所有不平衡（非嵌合）遗传异常的发生率（每万例中有4.0 - 5.2例）介于所有概念胎儿中估计的较高发生率（每万例中有9.1 - 15.8例）和新生儿中观察到的发生率（每万例中有1.5 - 2.5例）之间。这种趋势可能归因于与不平衡重排相关的胎儿死亡。然而，平衡（非嵌合）遗传异常的发生率（每万例中有26.0 - 28.0例）明显高于所有概念胎儿中的发生率（每万例中有13 - 16.7例）或所有活产中的发生率（每万例中有12.2 - 16.0例）。主要差异在于倒位的发生率。在羊膜穿刺术研究中使用了“显带”方法，但在大多数活产或流产研究中未使用，这可能至少部分导致了这些差异。在遗传异常中，父母年龄的一个趋势值得注意。父系遗传的平衡相互结构异常中，父亲年龄升高，但母系遗传的则不然。关于性别比例，在不平衡重排中，无论是遗传的还是突变的，女性比例均高于男性。在平衡重排中没有明显的性别差异。
