Abstract
Background: Congenital central hypoventilation syndrome (CCHS) is a rare autosomal dominant disorder caused by pathogenic variants in PHOX2B gene. Characteristics of neonatal-onset CCHS cases have not been well assessed. Our study aimed to expand current knowledge of clinical and genetic features of neonates with CCHS and provide data on the genotype-phenotype correlation.Methods: We made a retrospective analysis of 14 neonates carrying PHOX2B pathogenic variants from 2014 to 2019 and we reviewed previously published neonatal-onset cases. Clinical and genetic data were analyzed. Moreover, genotype-phenotype correlation analysis was performed.Results: We identified a total of 60 cases with neonatal-onset CCHS including 14 novel cases from our local cohort. Nearly 20% (18.2%, 10/55) of the patients were born prematurely. Nearly half (46.2%, 18/39) of the patients had abnormal family history. Polyhydramnios was observed in 21.3% (10/47) of the patients. About 90% of the patients manifested hypoventilation in the first week. Forty-six (76.7%) patients were classified as severer-CCHS. Gastrointestinal manifestations were observed in 71.7% of the patients. Approximately twofold more males than females were affected by Hirschprung disease (HSCR)/variant HSCR (75.8% vs 35%, P=0.003). Neural crest tumor occurred in 9.1% (4/44) patients. Half patients had PARMs in PHOX2B and the left had 23 distinct non-PARMs (NPARMs) with one novel variant (c.684dup). The prevalence of HSCR and mild-CCHS among patients with NPARMs was significantly greater than that of the patients with PARMs.Conclusions: This report provides a large cohort of neonatal-onset CCHS cases. The results indicate that severe hypoventilation and HSCR are frequently observed in this group. NPARMs accounted for half of the cohort with some genotypes tend to be associated with mild phenotype. Molecular testing in suspicious neonates and genetic counseling for CCHS families are highly recommended.
Paired-Like Homeobox Gene PHOX2B Non-Polyalanine Repeat Expansion Mutations: Genotype-Phenotype Correlation in Congenital Central Hypoventilation Syndrome and Later Onset-CCHS