Congenital central hypoventilation syndrome in Chinese population: Analysis of three new cases and review of the literature.

BACKGROUND: Congenital central hypoventilation syndrome (CCHS) is a rare autosomal dominant disease that is mainly caused by PHOX2B mutations. The purpose of this study is to analyze and summarize the clinical and genetic characteristics of CCHS patients in the Chinese population from our study and previous literature. METHODS: The potential pathogenic gene mutations of CCHS were identified and verified by next generation sequencing combined with Sanger sequencing, fluorescent probe PCR and capillary electrophoresis. The clinical characteristics and gene mutations of CCHS cases in Chinese population were summarized from our study and previous literature to explore the genotype-phenotype correlations. RESULTS: We identified 48 CCHS cases including three new cases from our report in China. Overall, 77.1% of the patients had PHOX2B polyalanine repeat expansion mutations (PARMs), and the remaining 22.9% had 10 distinct PHOX2B non-polyalanine repeat expansion mutations (NPARMs). Compared to those with PARMs, patients with NPARMs were more likely to have premature birth (54.5% vs. 2.8%, p < 0.001) and lower birth weight (33.3% vs. 3.2%, p = 0.030), with statistical significance. The patients with PARMs were more likely to have cardiovascular defects (64.9% vs. 27.3%, p = 0.063), cerebral hemorrhage (29.7% vs. 9.1%, p = 0.322) and seizures (37.8% vs. 9.1%, p = 0.151) than those with NPARMs, with no statistical significance. CONCLUSIONS: CCHS patients with PHOX2B NPARMs were more likely to have premature birth and low birth weight, while PHOX2B PARMs tended to be positively associated with the risk of cardiovascular defects, cerebral hemorrhage and seizures in Chinese population.