We report the case of a child from Central Brazil with global developmental delay (GDD), syndromic features, and absence of abnormal skin pigmentation, nail dystrophy, and leukoplakia of the oral mucosa, with a rearrangement at Xq28 harboring the DKC1 gene. GTC-banding revealed a male karyotype (46,XY) with no visible numerical or structural alterations. Chromosomal microarray analysis (CMA) showed a 0.36-Mb gain at Xq28 of maternal origin, encompassing 22 genes, including DKC1. Rearrangements and mutations involving this gene have been associated with dyskeratosis congenita, X-linked (OMIM 305000) and Hoyeraal-Hreidarsson syndrome. CMA was a powerful and efficient approach to identify a gain at Xq28 harboring the DKC1 gene in our patient with GDD syndromic features and no cutaneous alterations, suggesting that this variant is associated with the Hoyeraal-Hreidarsson syndrome.

中文翻译：

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一名患有全球性发育迟缓并伴有Hoyeraal-Hreidarsson综合征变异形式的儿童在Xq28处获得的拷贝数增加。

我们报告了一名来自巴西中部的儿童的病例，该儿童具有全球发育延迟（GDD），综合征特征，并且没有异常的皮肤色素沉着，指甲营养不良和口腔黏膜白斑，在Xq28处有DKK1基因重排。GTC带显示出男性核型（46，XY），没有可见的数字或结构改变。染色体微阵列分析（CMA）显示Xq28的母源来源增加了0.36-Mb，包括22个基因，包括DKC1。涉及该基因的重排和突变与先天性角化不全，X连锁（OMIM 305000）和Hoyeraal-Hreidarsson综合征有关。CMA是一种有力且有效的方法，可在我们的具有GDD综合征特征且无皮肤改变的患者中鉴定带有DKC1基因的Xq28的增益，