Cri-du-chat syndrome is characterized by facial dysmorphism, intellectual disability, and multiple congenital anomalies. Most cases occur de novo. Here, we report 3 siblings with cri-du-chat syndrome born to healthy parents. The proband was admitted to our clinic at the age of 6.5 years due to severe intellectual disability, facial dysmorphism, and heart defect. His karyotype showed a deletion of chromosome 5p. Microarray analysis revealed a 29-Mb deletion in chromosome 5p and a 4.7-Mb duplication in chromosome 19q. FISH analysis indicated an unbalanced translocation between 5p13.3 and 19q13.4. During follow-up, the second and the third child of the family were born with the same chromosome abnormality. Parental peripheral blood and skin fibroblast karyotypes as well as the FISH results using chromosome 5p- and 19q-specific subtelomeric probes were normal. FISH analysis of the father's sperm detected a 5p deletion in 12.8% of 200 cells, and microarray analysis confirmed the same unbalanced chromosome abnormality in a mosaic pattern. Uncultured peripheral blood and buccal smear of the father were also studied by FISH to exclude low-level mosaicism and in vitro culture effect. This is the first study that provides molecular evidence of paternal gonadal mosaicism of an unbalanced translocation detected in 3 siblings with cri-du-chat syndrome.
Mol Syndromol 2020;11:97-103

中文翻译：

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来自表型正常父母的三个Cri-du-Chat综合征后代。

Cri-du-chat综合征的特征是面部畸形，智力障碍和多种先天性异常。大多数情况是从头开始的。在这里，我们报告3个患有cri-du-chat综合征的兄弟姐妹，这些兄弟姐妹出生于健康的父母。由于严重的智力残疾，面部畸形和心脏缺陷，该先证者于6.5岁时进入我们的诊所。他的核型显示5p染色体缺失。微阵列分析显示在5p染色体上有29 Mb的缺失，在19q染色体上有4.7 Mb的重复。FISH分析表明5p13.3和19q13.4之间的不平衡易位。在随访期间，该家庭的第二个和第三个孩子出生时具有相同的染色体异常。父母外周血和皮肤成纤维细胞核型以及使用5p和19q染色体特异性亚端粒探针的FISH结果均正常。父亲精子的FISH分析在200个细胞的12.8％中检测到5p缺失，并且微阵列分析证实了马赛克图案中相同的不平衡染色体异常。FISH还研究了父亲的未培养外周血和颊涂片，以排除低水平镶嵌和体外培养效果。这是第一项为父本性腺性花叶病提供分子证据的证据，该父性性花叶病在3个患有cri-du-chat综合征的兄弟姐妹中发现了不平衡的易位。FISH还研究了父亲的未培养外周血和颊涂片，以排除低水平镶嵌和体外培养效果。这是第一项为父本性腺性花叶病提供分子证据的证据，该父性性花叶病在3个患有cri-du-chat综合征的兄弟姐妹中发现了不平衡的易位。FISH还研究了父亲的未培养外周血和颊涂片，以排除低水平镶嵌和体外培养效果。这是第一项为父本性腺性花叶病提供分子证据的证据，该父性性花叶病在3个患有cri-du-chat综合征的兄弟姐妹中发现了不平衡的移位。
Mol Syndromol 2020； 11：97-103