Our study aims to delineate the syndromology of Hunter syndrome (MPSII), by presenting three patients with different clinical courses, caused by different genetic mechanisms. Single-nucleotide variants (SNV) or small deletions encompassing the iduronate-2-sulfatase (IDS) gene are identified in the majority of affected individuals, while deletion of contiguous genes or whole IDS gene (described herein) has been reported rarely, mainly in patients with a severe Hunter syndrome presentation. There is; however, lack of reliable genotype-phenotype correlation, especially regarding anthropometric parameters, and thus our understanding of MPSII pathophysiology is not complete. On the basis of our observations, we would like to draw attention to the fact that neurological manifestations observed in patients with contiguous gene deletions, encompassing the IDS gene, may significantly differ from those observed in SNV. The phenotype is; however, difficult to predict and depends on the type (deletion/duplication), size (small/large) of aberration, and gene content. Moreover, it also has implications for genetic counseling, and recurrence risk in those families differs from the usual situation and must be clarified by parental chromosomal studies.

中文翻译：

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染色体畸变（包括全部和部分 IDS 缺失）患者亨特综合征的不同临床结果：早期诊断和咨询重要的是什么？

我们的研究旨在通过介绍由不同遗传机制引起的具有不同临床过程的三名患者来描述亨特综合征（MPSII）的综合征学。在大多数受影响个体中发现了包含艾杜糖醛酸-2-硫酸酯酶 (IDS) 基因的单核苷酸变异 (SNV) 或小缺失，而连续基因或整个 IDS 基因（本文所述）的缺失则很少有报道，主要是在患有严重亨特综合征的患者。有; 然而，缺乏可靠的基因型-表型相关性，特别是在人体测量参数方面，因此我们对 MPSII 病理生理学的理解并不完整。根据我们的观察，我们想提请注意这样一个事实：在包含 IDS 基因的连续基因缺失的患者中观察到的神经学表现可能与在 SNV 中观察到的显着不同。表型是；然而，很难预测，并且取决于畸变的类型（缺失/重复）、大小（小/大）和基因内容。此外，它对遗传咨询也有影响，这些家庭的复发风险与通常情况不同，必须通过父母染色体研究来澄清。