Survival in double aneuploidy involving trisomy 18 and sex chromosome trisomy: A case report of a 27-month-old child and a review of the literature

摘要

Maternal meiotic nondisjunction can cause autosomal trisomy, such as trisomy 13, 18, and 21, and parental meiotic nondisjunction or post-zygotic nondisjunction can cause sex chromosome trisomy, such as XXX (triple X syndrome), XXY (Klinefelter syndrome), and XYY (XYY syndrome). These coincidental chromosomal aberrations can lead to double aneuploidy involving autosomal trisomy and sex chromosome trisomy, with an incidence of less than 1 in 30,000 births (Nielsen and Wohlert 1991). Thus, double aneuploidy is extremely rare, and therefore there is too little epidemiological data to determine an appropriate treatment strategy. A case of a child with 48,XYY,+18 karyotype is presented along with a review of the literature to provide the basic epidemiological data for appropriate management strategies in double aneuploidy. A male infant was born at 41 weeks of gestation with a birth weight of 2266 g, and he was transported to our Neonatal Intensive Care Unit because of persistent respiratory distress. His clinical manifestations were consistent with trisomy 18, and echocardiography showed double-outlet right ventricle (DORV) with a subaortic ventricular septal defect and moderate pulmonary valvular stenosis. The lymphocyte karyotype was 48,XYY,+ 18 in 20 of 20 cells (Supporting Information Fig. 1). There have been only two case reports of live-born infants with the same karyotype, both of whom died within 4 months of birth (Felding and Kristoffersson 1981; Tennakoon et al. 2008). Based on these reports and careful discussion with the parents, surgical treatment was avoided, and conservative treatment was subsequently started, such as tube feeding and noninvasive bilevel positive airway pressure (BiPAP) ventilation for feeding difficulty and upper airway obstruction, respectively.