Background Complex chromosomal rearrangements are constitutive structural aberrations involving three or more breaks. They can be balanced or unbalanced and result in different outcomes, depending on deletion/duplication of genomic material, gene disruption, or position effects. Case presentation We report on a patient presenting with severe anemia, splenomegaly, mild intellectual disability and facial dysmorphisms harboring a 4.3 Mb duplication at 1p22.1p21.3 and a 2.1 Mb deletion at 8q21.3q22.1, involving RUNX1T1 gene. The healthy brother presented the same duplication of chromosome 1p as at 1p22.1p21.3. Conclusions The rearrangement found both these siblings resulted from malsegregation in the proband and recombination in her healthy brother of a balanced paternal complex chromosomal rearrangement. These results confirm RUNX1T1 as a causative gene for intellectual disability and suggest the 1p22.1p21.3 duplication is likely benign.

中文翻译：

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家族性染色体复合体重排证实 RUNX1T1 是智力障碍的致病基因，并表明 1p22.1p21.3 重复可能是良性的。

背景 复杂的染色体重排是组成性结构畸变，涉及三个或更多的断裂。它们可以是平衡的或不平衡的，并导致不同的结果，这取决于基因组材料的缺失/重复、基因破坏或位置效应。病例介绍 我们报告了一名患有严重贫血、脾肿大、轻度智力障碍和面部畸形的患者，在 1p22.1p21.3 处有 4.3 Mb 重复，在 8q21.3q22.1 处有 2.1 Mb 缺失，涉及 RUNX1T1 基因。健康的兄弟呈现出与 1p22.1p21.3 相同的染色体 1p 重复。结论 重排发现这两个兄弟姐妹都是由于先证者的错误分离和她健康的兄弟的平衡父系复合染色体重排的重组。