Yan Yousheng, Yi Bin, Liu Donghai, Zhao Fangping, Zhang Chuan, Chen Xue, Hao Shengju
Gansu Provincial Maternal and Child Health Care Hospital, Gansu Provincial Medical Genetics Center, Gansu Provincial Neonatal Intensive Care Unit, Lanzhou, Gansu 730050, P.R. China. Email:
Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2015 Oct;32(5):665-9. doi: 10.3760/cma.j.issn.1003-9406.2015.05.012.
OBJECTIVE To report on the phenotype of an infant with central hypoventilation syndrome (CCHS) and result of PHOX2B gene mutation analysis for the purpose of genetic counseling and prenatal diagnosis. METHODS Clinical data of an infant with CCHS was collected and analyzed. Potential mutation of PHOX2B gene was analyzed by amplified fragment length polymorphism (amp-FLP) and DNA sequencing. RESULTS The patient had typical clinical features of CCHS including frequent hypoventilation during sleeping, hypoxemia and hypercapnia which could be corrected by continuous ventilatory support. She also had repeated bruising and was difficult-to-wean, but without any cardiac, pulmonary, neuromuscular or brainstem lesions. DNA sequencing and amp-FLP of the PHOX2B gene showed that the patient has carried a polyalanine expansion repeat mutation (PARM) in exon 3. A 27 bp duplication was confirmed in the repeat sequence of 20 alanines by cloned and sequenced. This has led to an expansion of the repeat tract to 29 alanines. The genotype was therefore 20/29. CONCLUSION A patient with CCHS has been described. Mutation screening of PHOX2B gene can be used as an important support for diagnosis and genetic counseling for such patients.
目的 报告1例中枢性低通气综合征（CCHS）婴儿的表型及PHOX2B基因突变分析结果，以进行遗传咨询和产前诊断。方法 收集并分析1例CCHS婴儿的临床资料。采用扩增片段长度多态性（amp-FLP）和DNA测序分析PHOX2B基因的潜在突变。结果 该患者具有CCHS的典型临床特征，包括睡眠期间频繁的低通气、低氧血症和高碳酸血症，通过持续通气支持可得到纠正。她还反复出现瘀伤且难以撤机，但无任何心脏、肺部、神经肌肉或脑干病变。PHOX2B基因的DNA测序和amp-FLP显示该患者在外显子3中携带多聚丙氨酸扩展重复突变（PARM）。通过克隆和测序在20个丙氨酸的重复序列中确认了一个27 bp的重复。这导致重复序列扩展至29个丙氨酸。因此，基因型为20/29。结论 描述了1例CCHS患者。PHOX2B基因突变筛查可作为此类患者诊断和遗传咨询的重要依据。
