We present a patient with a de novo derivative chromosome 18 which includes a terminal deletion of 18p and a terminal duplication of 18q accompanied by a cryptic duplication of 18p. The girl had mild dysmorphic features such as micro-retrognathia, upslanted palpebral fissures, bilateral epicanthus, high palate, low-set ears, short neck, and full cheeks. She also had an H-type tracheoesophageal fistula which required surgery. Her cognitive and motor skills were delayed. Karyotype analysis showed an additional segment on the short arm of chromosome 18. Chromosomal microarray revealed a 7.3-Mb terminal loss from 18p11.32 to 18p11.23, a 22.2-Mb terminal gain from 18q21.31 to 18q23, and a 3.9-Mb interstitial gain from 18p11.22 to 18p11.21. We hypothesize that the mother has gonadal mosaicism for normal chromosome 18, der(18)dup(p11.22p11.21), and der(18)dup(p11. 22p11.21)inv(18)(p11.22q21.31), or both the terminal del/dup and the interstitial duplication occurred simultaneously.

中文翻译：

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具有从头衍生染色体 18 的患者的细胞遗传学、分子和表型特征以及文献回顾

我们介绍了一名具有从头衍生染色体 18 的患者，其中包括 18p 的末端缺失和 18q 的末端重复，并伴有 18p 的隐蔽重复。女孩有轻微的畸形特征，如微后颌、上斜的睑裂、双侧内眦、高腭、低位的耳朵、短颈和丰满的脸颊。她还有一个需要手术的H型气管食管瘘。她的认知和运动技能被延迟了。核型分析显示 18 号染色体短臂上有一个额外的片段。染色体微阵列显示从 18p11.32 到 18p11.23 有 7.3-Mb 的终末丢失，从 18q21.31 到 18q23 有 22.2-Mb 的终末增加，以及 3.9-Mb间隙增益从 18p11.22 到 18p11.21。我们假设母亲有正常 18 号染色体的性腺嵌合，der(18)dup(p11.22p11.21)，