||Background: In Benin, the diagnosis of G6PD deficiency is based on the biochemical test performed by
the quantitative spectrophotometry assay of the enzymatic activity. We used the results of the molecular gene test to
verify the reliability of the biochemical diagnostic test. The distribution of genes polymorphism associated with the
G6PD deficiency in neonates is also determined throughout the country. Material and Methods: This is a crosssectional descriptive study carried on with 178 neonates aged ≤7 days. Blood samples were screened for quantitative
G6PD enzymatic activity using Cypress Diagnostics kit (Cypress Diagnostics, Belgium). G6PD genotype analysis
was performed using specific primers for PCR amplification of G6PD gene containing the common African
mutations A376G, G202A, A542T, and T968C. We used Chi-2 test to compare the means of qualitative data and
Student’s t-test to ascertain difference between group’s characteristics. A p-value of <0.05 was deemed significant.
Results: The mean value of normal G6PD activity was 16.25 U/g Hb. Enzyme activity was significantly lower in
female newborns of genotype A-(376/202) /A-(376/202) (p<0.01) and in males genotype A-(376/202) (p<0.001). The
probability of being deficient when the test of enzymatic activity is positive among the true deficit (Se) was 0.42.
The probability of being non-deficient when the test is negative among the non-deficient (Sp) was 0.89, that of being
deficient when the test is positive (PPV) was 0.52 and the probability of being non-negative when the test is negative
(VPN) was 0.85. Genotypes B/B, A/B, A/A, A-(376/202)/B, A-(376/202)/A, A-(376/202)/A-(376/202) were identified in female
newborns with respective proportion of 39.56%, 13.19%, 7.69%, 24.18%, 13.19% and 2.20%. In males, 64.37%
were genotype B, 9.20% genotype A and 26.44% genotype A-(376/202). The northern departments had the highest
frequencies of G6PD A-(376/202) (33.18% to 37.73%) while the lowest levels were seen in the south (25.58% to
28.62%). Conclusion: Enzymatic activity showed good diagnostic value in male subjects but not in heterozygous
female. The highest frequency of G6PD A-(376/202) mutation was in the North Benin.