Identification of G6PD Mediterranean mutation by amplification refractory mutation system.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common X chromosome-linked hereditary enzymopathy in humans. The authors have developed an amplification refractory mutation system (ARMS) to detect the G6PD Mediterranean mutation (nt. 563 C-->T) that is the most frequent among Caucasian population.
METHODS: Specific forward polymerase chain reaction (PCR) primers, within exon 6 of the G6PD gene, were designed: ARMS M complementary to the mutated DNA sequence and ARMS N complementary to the wild-type DNA. They were paired with a common reverse primer. The new method was validated using known DNA samples from 72 G6PD-deficient patients carrying the G6PD Mediterranean mutation ascertained by the restriction enzyme analysis. The ARMS test was performed on DNA extracted both from blood or saliva samples.
RESULTS: The ARMS test showed an excellent reproducibility and a complete concordance with the endonuclease cleavage reference method. At the same time, it is more rapid and less expensive.
CONCLUSIONS: The described molecular test may be a method of choice to identify the G6PD Mediterranean mutation. It could also be helpful to obtain a definite diagnosis of G6PD Mediterranean heterozygotes, which is not feasible by using red blood cell enzyme activity measurements.