BACKGROUND Double aneuploidies - especially in combination with structural aberrations - are extremely rare among liveborns. The most frequent association is that of Down (DS) and Klinefelter syndromes (KS). We present the case of a male newborn with a unique 47,XY,+ 21[80%]/48,XY,+i(X)(q10),+ 21[20%] karyotype, hypothesize about his future phenotype, discuss the aspects of management and review the literature. CASE PRESENTATION The additional association of isochromosome Xq (i(X)(q10)) could be the result of a threefold non-disjunction event. 47,XY,+i(X)(q10) KS is not common and its symptoms differ from the classical KS phenotype. In combined DS and i(X)(q10) KS, the anticipatory phenotype is not simply the sum of the individual syndromic characteristics. This genotype is associated with higher risk for several diseases and certain conditions with more pronounced appearance: emotional and behavioral disorders; poorer mental and physical quality of life; lower muscle mass/tone/strength; connective tissue weakness; muscle hypotonia and feeding difficulties; osteopenia/-porosis with earlier beginning and faster progression; different types of congenital heart diseases; more common occurrence of hypertension; increased susceptibility to infections and female predominant autoimmune diseases; higher risk for hematological malignancies and testicular tumors. CONCLUSIONS In multiple aneuploidies, the alterations have the potential to weaken or enhance each other, or they may not have modifying effects at all. Prenatal ultrasound signs are not obligatory symptoms of numerous chromosomal anomalies (specifically those involving supernumerary sex chromosomes), therefore combined prenatal screening has pertinence in uncomplicated pregnancies as well.

中文翻译：

---

当合并Down-和47，XY，+ i（X）（q10）Klinefelter综合征时，我们应考虑什么？男性新生儿的独特病例和文献复习。

背景技术双非整倍体，特别是与结构畸变结合的双非整倍体在活产婴儿中极为罕见。最常见的关联是唐氏（DS）和克林费尔特综合征（KS）。我们提出一个男性新生儿的病例，该病例具有独特的47，XY，+ 21 [80％] / 48，XY，+ i（X）（q10），+ 21 [20％]核型，并假设其未来的表型。管理方面，并复习文献。案例介绍同染色体Xq（i（X）（q10））的其他关联可能是三重非析取事件的结果。47，XY，+ i（X）（q10）KS不常见，其症状与经典KS表型不同。在DS和i（X）（q10）KS的组合中，预期表型不仅是各个症状特征的总和。这种基因型与多种疾病和某些症状更为明显的某些疾病的较高风险有关：情绪和行为障碍；心理和身体生活质量较差；较低的肌肉质量/音调/强度；结缔组织无力；肌张力低下和进食困难; 骨质疏松/疏松症起病较早，进展更快；不同类型的先天性心脏病；高血压多见；对感染和女性主要自身免疫性疾病的敏感性增加；血液系统恶性肿瘤和睾丸肿瘤的风险更高。结论在多个非整倍体中，这些改变有可能相互削弱或增强，或者根本没有修饰作用。