Study of GCN repeats of PHOX2B gene among individuals from southwest China and diagnosis of two patients with Congenital central hypoventilation syndrome
10.3760/cma.j.cn511374-20221209-00854
- VernacularTitle:西南地区人群 PHOX2B基因GCN重复变异的调查以及2例先天性中枢性低通气综合征患儿的诊断
- Author:
Shengfang QIN
1
;
Mengling YE
;
Yan YIN
;
Jin WANG
;
Xueyan WANG
;
Zhuo ZHANG
;
Ximin CHEN
;
Mengjia YAN
;
Yuxia HE
;
Danying YI
;
Qin DENG
Author Information
1. 四川省妇幼保健院医学遗传与产前诊断科，成都 610045
- Keywords:
PHOX2B gene;
GCN repeats;
Gene sequencing;
Capillary electrophoresis;
Congenital central hypoventilation syndrome
- From:
Chinese Journal of Medical Genetics
2024;41(1):32-37
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To study the trinucleotide repeats of GCN (GCA, GCT, GCC, GCG) encoding Alanine in exon 3 of the PHOX2B gene among healthy individuals from southwest China and two patients with Congenital central hypoventilation syndrome (CCHS). Methods:The number and sequence of the GCN repeats of the PHOX2B gene were analyzed by capillary electrophoresis, Sanger sequencing and cloning sequencing of 518 healthy individuals and two newborns with CCHS, respectively. Results:Among the 1036 alleles of the 518 healthy individuals, five alleles were identified, including (GCN) 7, (GCN) 13, (GCN) 14, (GCN) 15 and (GCN) 20. The frequency of the (GCN) 20 allele was the highest (94.79%). And five genotypes were identified, which included (GCN) 7/(GCN) 20, (GCN) 13/(GCN) 20, (GCN) 14/(GCN) 20, (GCN) 15/(GCN) 20, (GCN) 20/(GCN) 20. The homozygous genotypes were all (GCN) 20/(GCN) 20, and the carrier rate was 89.58%. Four GCN sequences of the (GCN) 20 homozygous genotypes were identified among the 464 healthy individuals. The GCN repeat numbers in the exon 3 of the PHOX2B gene showed no significant difference between the expected and observed values, and had fulfilled the, Hardy-Weinberg equilibrium. The genotypes of the two CCHS patients were (GCN) 20/(GCN) 25 and (GCN) 20/(GCN) 30, respectively. Conclusion:It is important to determine the GCN repeats and genotypic data of the exon 3 of the PHOX2B gene among the healthy individuals. The number of GCN repeats in 518 healthy individuals was all below 20. The selection of appropriate methods can accurately detect the polyalanine repeat mutations (PARMs) of the PHOX2B gene, which is conducive to the early diagnosis, intervention and treatment of CCHS.
