Phenotypic and genotypic spectra of patients with glucose-6-phosphate dehydrogenase deficiency gene known pathogenic variants: a single-center study

Abstract

Objective: To analyze the hotspots of known pathogenic disease-causing variants of glucose-6-phosphate dehydrogenase (G6PD) and the phenotype spectrum of neonatal patients with known pathogenic disease-causing variants of G6PD. Methods: The known pathogenic disease-causing variants of G6PD were collected from Human Gene Mutation Database. Screening was performed for these variants among the 7 966 cases (2 357 neonatal, 5 609 non-neonatal) in the database of sequencing at Molecular Diagnosis Center, Children's Hospital of Fudan University. All these samples were from patients suspected with genetic disorder. The database contained Whole Exon Sequencing data and Clinical Exon Sequencing data. We screened out the patients with known pathogenic disease-causing variants of G6PD, analyzed the hotspot of G6PD and the phenotype spectrum of neonatal patients with known pathogenic disease-causing variants of G6PD. Results: (1) Among the next generation sequencing data of the 7 966 samples, 86 samples (1.1%) were detected as positive for the known pathogenic disease-causing variants of G6PD (positive samples set). In the positive sample set, 51 patients (33 males, 18 females) were newborn babies. Forty-three patients (26 males, 17 females) had the enzyme activity data of G6PD. (2) Among the 86 samples, Arg463His, Arg459Leu, Leu342Phe, Val291Met were the leading 4 disease-causing variants found in 72 samples (84%). (3) Male neonatal patients with the same variants had the statistically significant differences in enzyme activity: among 13 patients with Arg463His, enzyme activity of 9 patients was ranked as grade Ⅲ, 1 case ranked as Ⅳ, 3 cases had no activity data;among 10 patients with Arg459Leu, enzyme activity of 4 patients was ranked as Ⅱ, 4 cases ranked as Ⅲ, 2 cases had no activity data;among 2 patients with His32Arg, enzyme activity of one patient was ranked as Ⅱ, another was Ⅲ. Male neonatal patients with the same mutation and enzyme activity also had the statistically significant differences in phenotype spectrum: among 9 patients with Arg463His and level Ⅲ enzyme activity, 6 presented hyperbilirubinemia, 2 met the criteria for exchange transfusion therapy, 2 showed hemolysis;among 4 patients with Arg459Leu and level Ⅱ enzyme activity, 3 presented hyperbilirubinemia;among 4 patients with Arg459Leu and level Ⅲ enzyme activity, 2 presented hyperbilirubinemia, 1 met the standard of exchange transfusion therapy;among 3 patients with Val291Met and level Ⅲ enzyme activity, 1 presented hyperbilirubinemia. Conclusions: Arg463His, Arg459Leu, Leu342Phe, Val291Met were the hotspots variants for the G6PD. Patients with the same G6PD variants and sex present different phenotype, patients with the same G6PD variants, sex and enzyme activity also present different phenotype .