rs5030868, also known as c.653C>T, p.Ser218Phe and S218F, is a SNP located on the X-Chromosome and associated with moderate to severe Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency. Often referred to as the “Mediterranean variant”, the 563C->T mutation encodes a non-synonymous Serine to Phenylalanine substitution at Amino Acid position 188 (S188F) resulting in reduced catalytic efficiency and stability G6PD [PMID 3393536]. In red blood cells, G6PD acts as the primary electron source for reactions that neutralize reactive oxygen species; thus the red blood cells of G6PD deficient individuals are especially susceptible to damage from oxidative stress [PMID 18177777]. The Mediterranean variant of G6PD has been associated with acute hemolytic anemia induced by the ingestion of fava beans, glibenclamide, primaquine, dapsone, and Aspirin among others. [PMID 8562390] [PMID 2502894][PMID 14945981][PMID 19112496]
Hemizygous males and homozygous females exhibit moderate to severe symptoms of G6PD deficiency, while heterozygous females may exhibit symptoms to varying degrees due to random inactivation of X-Chromosomes. This Mediterranean variant is primarily found in individuals with Mediterranean or Middle Eastern ancestry. It is suspected to be protective against malaria and to have been under positive selection in the past [PMID 86896].
See also OMIM 305900.0006