Mucopolysaccharidosis type II (MPS II, Hunter syndrome) is a rare, X-linked recessive multisystem lysosomal storage disease due to iduronate-2-sulfatase enzyme deficiency. We presented three unrelated Slovenian patients with the severe form of MPS II that received three different management approaches: natural course of the disease without received specific treatment, enzyme replacement therapy (ERT), and hematopoietic stem cell transplantation (HSCT). The decision on the management depended on disease severity, degree of cognitive impairment, and parent's informed decision. The current benefits of MPS II treatments are limited. The lifelong costly intravenous ERT brings significant benefits but the patients with severe phenotypes and neurological involvement progress to cognitive decline and disability regardless of ERT, as demonstrated in published reviews and our case series. The patient after HSCT was the only one of the three cases reported to show a slowly progressing cognitive development. The type of information from the case series is insufficient for generalized conclusions, but with advanced myeloablative conditioning, HSCT may be a preferred treatment option in early diagnosed MPS II patients with the severe form of the disease and low disease burden at the time of presentation.

粘多糖贮积症 II 型（MPS II，Hunter 综合征）是一种罕见的 X 连锁隐性多系统溶酶体贮积病，由艾杜糖醛酸-2-硫酸酯酶缺乏所致。我们介绍了三名无关的斯洛文尼亚重症 MPS II 患者，他们接受了三种不同的管理方法：未经特殊治疗的疾病自然病程、酶替代疗法 (ERT) 和造血干细胞移植 (HSCT)。治疗决定取决于疾病严重程度、认知障碍程度和父母的知情决定。MPS II 治疗的当前益处是有限的。终生昂贵的静脉内 ERT 带来了显着的好处，但无论 ERT 如何，具有严重表型和神经系统受累的患者都会进展为认知能力下降和残疾，如已发表的评论和我们的案例系列所示。HSCT 后的患者是报告的三个病例中唯一一个表现出缓慢进展的认知发展的病例。来自病例系列的信息类型不足以得出一般性结论，但对于晚期诊断的 MPS II 患者，HSCT 可能是一种首选的治疗选择，这些患者具有严重的疾病形式和就诊时的低疾病负担。