Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan.
Taiwan J Obstet Gynecol. 2011 Mar;50(1):48-57. doi: 10.1016/j.tjog.2011.02.001.
To present perinatal findings, modes of ascertainments, and modes of segregation in unbalanced reciprocal translocations detected at amniocentesis.
Between January 1987 and July 2010, 40 cases with unbalanced reciprocal translocations were diagnosed by amniocentesis at Mackay Memorial Hospital, Taipei, Taiwan. The 40 cases originated from 29 families; 21 families with one case, 7 families with two cases, and 1 family with five cases.
Of 40 cases, 33 (82.5%) presented fetal ultrasound abnormalities and 7 (17.5%) presented no ultrasound abnormalities. Of 40 cases, 36 (90%) had a segregation mode of adjacent-1 2:2 segregation, 3 (7.5%) had a segregation mode of 3:1 segregation with tertiary trisomy, and 1 (2.5%) had a segregation mode of 3:1 segregation with tertiary monosomy. Of 29 families, 7 (24.1%) had de novo translocations and 22 (75.9%) had inherited translocations. In seven de novo cases, the main modes of ascertainments included abnormal ultrasound findings (n = 5) and advanced maternal age (n = 2). In 22 inherited families, the main modes of first ascertainment included abnormal ultrasound findings (n = 8), a previous aneuploid child (n = 8), advanced maternal age (n = 4), parental carrier status (n = 1), and abnormal maternal serum screening results (n = 1). Among 22 inherited families, 9 (40.9%) had a known parental carrier status, but 13 (59.1%) were unaware of parental carrier status at amniocentesis.
Unbalanced reciprocal translocations detected at amniocentesis are frequently associated with abnormal ultrasound findings. Prenatal diagnosis of an unbalanced translocation may incidentally detect a balanced translocation in the family. Prenatal diagnosis of fetal structural abnormalities should alert structural chromosome rearrangements and prompt cytogenetic analysis of the fetus and parents if necessary.
介绍在羊膜穿刺术检测到的不平衡相互易位中的围产期发现、确定方式和分离方式。
1987 年 1 月至 2010 年 7 月期间，在台北马偕纪念医院通过羊膜穿刺术诊断出 40 例不平衡相互易位病例。这 40 例病例来自 29 个家庭；1 个家庭有 5 例，7 个家庭有 2 例，21 个家庭有 1 例。
40 例中，33 例（82.5%）出现胎儿超声异常，7 例（17.5%）无超声异常。40 例中，36 例（90%）分离方式为邻-1 2：2 分离，3 例（7.5%）分离方式为 3：1 分离伴三体性，1 例（2.5%）分离方式为 3：1 分离伴单体性。29 个家庭中，7 例（24.1%）为新发易位，22 例（75.9%）为遗传易位。7 例新发病例中，主要确定方式包括超声异常发现（n=5）和高龄产妇（n=2）。在 22 个遗传家族中，主要的首次确定方式包括超声异常发现（n=8）、先前的非整倍体胎儿（n=8）、高龄产妇（n=4）、父母携带者状态（n=1）和异常母体血清筛查结果（n=1）。在 22 个遗传家族中，9 例（40.9%）已知父母携带者状态，但 13 例（59.1%）在羊膜穿刺术时不知道父母携带者状态。
在羊膜穿刺术检测到的不平衡相互易位常与超声异常有关。不平衡易位的产前诊断可能偶然发现家族中的平衡易位。胎儿结构异常的产前诊断应警惕结构染色体重排，并在必要时对胎儿和父母进行细胞遗传学分析。
