ClinVar

Description

The G6PD c.1039G>A (p. Glu347Lys) missense variant, which is also commonly reported as c.949G>A (p.Glu317Lys) and G6PD Kerala-Kalyan, and less commonly reported as G6PD Jamnagar or Rohini, is one of the most common disease-causing variants in South Asian populations. The p.Glu347Lys variant has been estimated to account for between 1.1% and 24.5% of disease-causing alleles in the Indian population (Sukumar et al. 2004; Devendra et al. 2020). This variant has also been reported in affected individuals of Bangladeshi, Burmese, and Thai descent (Nuchprayoon et al. 2008; Sarker et al. 2016). The p.Glu347Lys variant is typically associated with glucose-6-phosphate dehydrogenase enzyme activity levels between 10% - 60% of wild type and is considered a class III variant according the WHO classification system for G6PD variants (Minucci et al. 2012; Harcke et al. 2019). The p.Glu347Lys variant is reported at a frequency of 0.01138 in the South Asian population of the Genome Aggregation Database. This allele frequency is high but is consistent with the disease prevalence estimates. Although the consequences of p.Glu347Lys have not been characterized experimentally, the Glu347 residue is known to interact with Lys275, which is the site of the another disease-causing variant, p.Lys275Asn or G6PD Bangkok. This interaction forms a salt bridge between subunits B and C of the tetrameric structure in wild-type G6PD (Boonyuen et al. 2017). Based on the collective evidence and application of the ACMG criteria, the p. Glu347Lys variant is classified as pathogenic for glucose-6-phosphate dehydrogenase deficiency.