Glucose-6-phosphate dehydrogenase deficiency (G6PD) is the most common enzyme 
pathology in humans; it is X-linked inherited and causes neonatal 
hyperbilirubinaemia, chronic nonspherocytic haemolytic anaemia and drug-induced 
acute haemolytic anaemia. G6PD deficiency has scarcely been studied in the 
northern region of Mexico, which is important because of the genetic 
heterogeneity described in Mexican population. Therefore, samples from the 
northern Mexico were biochemically screened for G6PD deficiency, and PCR-RFLPs, 
and DNA sequencing used to identify mutations in positive samples. The frequency 
of G6PD deficiency in the population was 0.95% (n = 1993); the mutations in 86% 
of these samples were G6PD A(-202A/376G), G6PDA(-376G/968C) and G6PD 
Santamaria(376G/542T). Contrary to previous reports, we demonstrated that G6PD 
deficiency distribution is relatively homogenous throughout the country (P = 
0.48336), and the unique exception with high frequency of G6PD deficiency does 
not involve a coastal population (Chihuahua: 2.4%). Analysis of eight 
polymorphic sites showed only 10 haplotypes. In one individual we identified a 
new G6PD mutation named Mexico DF(193A>G) (rs199474830), which probably results 
in a damaging functional effect, according to PolyPhen analysis. Proteomic 
impact of the mutation is also described.