Abstract：
Zimmermann-Laband Syndrome (ZLS; MIM 135500) is a rare genetic disorder with the main clinical manifestations of gingival fibromatosis and finger/toe nail hypoplasia. KCNH1 (potassium channel, voltage-gated, subfamily H, member-1), KCNN3 (potassium channel, voltage-gated, subfamily H, member-3) and ATP6V1B2 (ATPase H+ transporting V1 subunit B2) genes are considered causative genes for ZLS. However, there are limited reports about the diverse clinical presentation and genetic heterogeneity. Reporting more information on phenotype-genotype correlation and the treatment of ZLS is necessary. This case reported a 2-year-old patient with gingival enlargement that failure of eruption of the deciduous teeth and severe hypoplasia of nails. Based on a systemic examination and a review of the relevant literature, we made an initial clinical diagnosis of ZLS. A novel pathogenic variant in the KCNH1 gene was identified using whole-exome sequencing to substantiate our preliminary diagnosis. The histopathological results were consistent with gingival fibromatosis. Gingivectomy and gingivoplasty were performed under general anesthesia. After surgery, the gingival appearance improved significantly, and the masticatory function of the teeth was restored. After 2-year follow-up, the gingival showed slightly hyperplasia. Systemic examination and gene sequencing firstly contribute to provide information for an early diagnosis for ZLS, then timely removal of the hyperplastic gingival facilitates the establishment of a normal occlusal relationship and improves oral aesthetics.
摘要：
Zimmermann-Laband综合征（ZLS;MIM135500）是一种罕见的遗传性疾病，主要临床表现为牙龈纤维瘤病和指/趾指甲发育不全。KCNH1（钾通道，电压门控，亚科H,member-1),KCNN3（钾通道，电压门控，亚科H,成员3）和ATP6V1B2（ATPaseH转运V1亚基B2）基因被认为是ZLS的致病基因。然而,关于不同临床表现和遗传异质性的报道有限.有必要报告有关表型-基因型相关性和ZLS治疗的更多信息。该病例报道了一名2岁的牙龈肿大患者，乳牙萌出失败，指甲严重发育不全。在系统检查和相关文献综述的基础上，我们对ZLS进行了初步临床诊断。使用全外显子组测序鉴定了KCNH1基因中的一种新的致病性变体，以证实我们的初步诊断。组织病理学结果与牙龈纤维瘤病一致。全麻下进行牙龈切除术和牙龈成形术。手术后,牙龈外观明显改善，牙齿的咀嚼功能得到恢复。经过2年的随访,牙龈稍有增生。系统检查和基因测序首先有助于为ZLS的早期诊断提供信息。然后及时去除增生性牙龈有助于建立正常的咬合关系，并改善口腔美学。
