Re-evaluation of methaemoglobin reduction as a screening procedure for glucose-6-phosphate dehydrogenase (G6PD)

Methaemoglobin reduction method is considered to be an old method of qualitative analysis of glucose-6-phosphate dehydrogenase with low specificity and sensitivity and as such, many are sceptical about the reliability of the outcome of the result of the methodology.The aims of this study were to determine the sensitivity and specificity of methaemoglobin reduction method and examine its suitability as a routine method for the screening of glucose-6-phosphate dehydrogenase in this environment. One hundred children were recruited into the study which was conducted over a period of one year. The children (males and females) were aged between 1 day and 15 years. G6PD screening by methaemoglobin reduction method was carried out on all the subjects, while G6PD qualitative assay using G6PD assay kits by Biolabo (France), was carried out in the first 15 subjects who were G6PD deficient by the qualitative screening and the first 15 subjects who were G6PD normal. This was to compare the qualitative with the quantitative assay results and thereby determine the sensitivity and specificity of the methaemoglobin reduction method. The sensitivity and specificity of methaemoglobin reduction test was found to be 93.3 percent each. The results of the qualitative methaemoglobin reduction test for the G6PD deficiency compared well with the quantitative enzymatic assay. With sensitivity and specificity each of 93.3%, the simple qualitative test is dependable and therefore suitable for screening for G6PD.