https://www.selleckchem.com/products/mi-503.html To summarize the clinical characteristics of two children with nonclassical 21 hydroxylase deficiency (NC-21OHD) due to variants of CYP21A2 gene promoter region. Clinical characteristics and the results of genetic testing were reviewed. The main clinical manifestations of the two children included precocious puberty with poor bone age/progression control and menstrual disorder with hirsutism. Patient 1 had compound heterozygous variants for -126C>T, -113G>A, -110T>C and p.I173N; her mother was heterozygous for -126C>T, -113G>A and -110T>C, and her father was heterozygous for p.I173N. Patient 2 had compound heterozygous variants for -126C>T, -113G>A and p.I2G, whose mother was heterozygous for -126C>T and -113G>A, and father was heterozygous for p.I2G. Diagnosis of NC-21OHD should be considered for children with hirsutism, menstrual disorder and poor bone age/progression control. The promoter region of CYP21A2 gene should be analyzed when no variant is detected in its coding regions. Diagnosis of NC-21OHD should be considered for children with hirsutism, menstrual disorder and poor bone age/progression control. The promoter region of CYP21A2 gene should be analyzed when no variant is detected in its coding regions. To develop a cell-based system for the diagnosis of vitamin K-dependent coagulation factor deficiency 1 (VKCFD1). In HEK293 cells stably expressing the reporter gene FIX-Gla-PC, the gamma-glutamyl carboxylase (GGCX) gene was knocked out by using CRISPR/Cas9 technology. Enzyme-linked immunosorbent assay (ELISA), DNA sequencing and Western blotting were used to identify the GGCX gene knockout cells. A quickchange point variant method was used to construct the GGCX variant. ELISA was used to assess the influence of GGCX variant on the activity of reporter gene. Two monoclonal cell lines with no reporter activity by ELISA was identified. Edition and knockout of the GGCX gene was confirmed by DNA sequencing and W