Lele Hou1, Liyang Liang1, Shaofen Lin1, Hui Ou1, Zulin Liu1, Siqi Huang1, Lina Zhang2, Zhe Meng3. 1. Department of Pediatrics, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, 107 Yan Jiang West Road, Guangzhou, China. 2. Department of Pediatrics, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, 107 Yan Jiang West Road, Guangzhou, China. Electronic address: zhlina5@mail.sysu.edu.cn. 3. Department of Pediatrics, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, 107 Yan Jiang West Road, Guangzhou, China. Electronic address: mengzhe@mail.sysu.edu.cn.
Abstract
OBJECTIVE: 21-hydroxylase deficiency (21-OHD) caused by mutation in CYP21A2 gene is the most common form of Congenital adrenal hyperplasia (CAH). This study aimed to analyze the gene mutation frequency and the phenotype-genotype correlation of 21-OHD patients from southern China. METHOD: The clinical features, laboratory tests and gene mutational analysis of 84 patients with 21-OHD were retrospectively investigated. Subsequently, the correlation between phenotypes and genotypes of these patients was analyzed. RESULTS: 59 of 84 cases of 21-OHD (70.2%) were classified as salt-wasting (SW) forms presenting adrenal crisis or other signs of salt loss at the age between neonatal period and 2 months, and other 25 cases were classified as simple virilizing (SV) forms. Mutations of CYP21A2 gene on both alleles were found in all 84 patients (168 alleles). The most common types of mutations included micro-conversions (129/168, 76.8%), large gene conversions and deletions (23/168, 13.7%), and bona fide point mutations (16/168, 9.5%). In increasing order of frequency, the most common micro-conversions were I2G (41.1%), p.I172N (13.1%), p.R356W (7.7%), p.Q318* (7.7%) and E6 Cluster (3.0%). Genotypes and phenotypes correlated in 86.1% of the patients analyzed. CONCLUSION: Micro-conversions were the most common types of CYP21A2 gene mutations in our study, and the frequency of the identified mutations was not significantly different compared with most other Chinese areas and different ethnic regions. However, fewer large gene conversions and deletions were found compared to studies in other ethnic populations. Genotype-phenotype correlation was found in patients with the SW and SV forms of 21-OHD. This study expanded the number of mutations affecting CYP21A2 gene in Chinese patients with 21-OHD, providing additional information for a precise clinical diagnosis and genetic counseling.
OBJECTIVE:21-hydroxylase deficiency (21-OHD) caused by mutation in CYP21A2 gene is the most common form of Congenital adrenal hyperplasia (CAH). This study aimed to analyze the gene mutation frequency and the phenotype-genotype correlation of 21-OHDpatients from southern China. METHOD: The clinical features, laboratory tests and gene mutational analysis of 84 patients with 21-OHD were retrospectively investigated. Subsequently, the correlation between phenotypes and genotypes of these patients was analyzed. RESULTS: 59 of 84 cases of 21-OHD (70.2%) were classified as salt-wasting (SW) forms presenting adrenal crisis or other signs of salt loss at the age between neonatal period and 2 months, and other 25 cases were classified as simple virilizing (SV) forms. Mutations of CYP21A2 gene on both alleles were found in all 84 patients (168 alleles). The most common types of mutations included micro-conversions (129/168, 76.8%), large gene conversions and deletions (23/168, 13.7%), and bona fide point mutations (16/168, 9.5%). In increasing order of frequency, the most common micro-conversions were I2G (41.1%), p.I172N (13.1%), p.R356W (7.7%), p.Q318* (7.7%) and E6 Cluster (3.0%). Genotypes and phenotypes correlated in 86.1% of the patients analyzed. CONCLUSION: Micro-conversions were the most common types of CYP21A2 gene mutations in our study, and the frequency of the identified mutations was not significantly different compared with most other Chinese areas and different ethnic regions. However, fewer large gene conversions and deletions were found compared to studies in other ethnic populations. Genotype-phenotype correlation was found in patients with the SW and SV forms of 21-OHD. This study expanded the number of mutations affecting CYP21A2 gene in Chinese patients with 21-OHD, providing additional information for a precise clinical diagnosis and genetic counseling.
Authors: Hedi L Claahsen-van der Grinten; Phyllis W Speiser; S Faisal Ahmed; Wiebke Arlt; Richard J Auchus; Henrik Falhammar; Christa E Flück; Leonardo Guasti; Angela Huebner; Barbara B M Kortmann; Nils Krone; Deborah P Merke; Walter L Miller; Anna Nordenström; Nicole Reisch; David E Sandberg; Nike M M L Stikkelbroeck; Philippe Touraine; Agustini Utari; Stefan A Wudy; Perrin C White Journal: Endocr Rev Date: 2022-01-12 Impact factor: 19.871