OBJECTIVETo avoid the interference of ABCD1 pseudogenes, the amplification refractory mutation system (ARMS) was used to analyze the mutation of ABCD1 gene in the molecular diagnosis of X-linked adrenoleukodystrophy (ALD).

METHODSThe upstream primers (wild primer and mutation primer) were designed according to the principle of primer-design in ARMS. In addition, a common downstream primer was designed in the same way to discriminate ABCD1 gene from its prologous pseudogenes. The genomic DNA isolated from the peripheral blood leukocytes of the family members and normal controls was amplified by PCR.

RESULTSIn double ARMS, a specific product of 107bp could be amplified from genomic DNA of the patient with R617C mutation in ABCD1 gene and his mother, while the same product was not found when the genomic DNA of the patient's father and normal controls was used. Thus, the interference of ABCD1 pseudogenes in molecular diagnosis of ALD was excluded successfully at genomic DNA level.

CONCLUSIONDouble ARMS is a quick and effective method to eliminate the interference of the pseudogenes in detecting ABCD1 gene mutations.