Detection of three common G6PD gene mutations in Chinese individuals by probe melting curves

Rapid genotyping of two common G6PD variants, African (A-) and Mediterranean, by high-resolution melting analysis

OBJECTIVES

The Mediterranean and A(-) G6PD variants are particularly prevalent in Africa and Southern Europe. Our study was aimed to develop an assay for the rapid genotyping of these two variants by HRM.

METHODS

After PCR reactions corresponding to the G6PD Mediterranean (exon 6), G6PD (A-) (exon 4) and G6PD (A-) (exon 5) mutations, amplicons were submitted to HRM. This protocol was applied to a cohort of 132 patients suffering from sickle cell disease.

RESULTS

Wild, homozygous or hemizygous and heterozygous states were fully discriminated by HRM for all three mutations. HRM results were in total accordance with DNA sequencing for 22 patients of our cohort with a 'A' genotype: presence of the (A-) (exon 5) mutation but absence of the (A-) (exon 4) mutation.

CONCLUSIONS

Our HRM protocols allow a rapid, simple and cost-effective screening of G6PD deficiency in patients originating from the Mediterranean and the African areas.

Glucose-6-phosphate dehydrogenase laboratory assay: How, when, and why?

Glucose 6-phosphate dehydrogenase (G6PD) deficiency is the most common defect of red blood cells. Although some different laboratory techniques or methods are employed for the biochemical screening, a strict relationship between biochemists, clinicians, and molecular biologists is necessary for a definitive diagnosis. This article represents an overview on the current laboratory tests finalized to the screening or to the definitive diagnosis of G6PD-deficiency, underlying the problems regarding the biochemical and molecular identification of heterozygote females other than those regarding the standardization of the clinical and laboratory diagnostic procedures. Finally, this review is aimed to give a flow-chart for the complete diagnostic approach of G6PD-deficiency.

A real-time multiplex SNP melting assay to discriminate individuals

A method that quickly and inexpensively differentiates crime scene samples from multiple donors would expedite casework analysis by allowing the selection of probative items requiring comprehensive testing. This new method need not be perfectly definitive nor give a complete 13 locus short tandem repeat (STR) profile; it simply must be able to differentiate between most victim and suspect samples. We describe the development of multiplex, single nucleotide polymorphism (SNP), fluorescence resonance energy transfer-based real-time polymerase chain reaction (PCR) assays to fulfill this need. Dual probes, one fluorescently labeled and the other labeled with a quencher, are monitored during a melt analysis to reveal an increase in fluorescence, which allows the assessment of the two SNP alleles. Two alternate 6-plex assays (with and without gender determination) have been developed for the six-color RG6000 real-time instrument (Corbett Robotics, Inc.) and one seven SNP plus gender assay (performed as two 4-plex assays, one with gender the other without) have been developed for use in four/five color real-time instruments. This technique can discriminate between 95% and 99% of samples from different individuals. This assay is fast (approximately 2 h), much less expensive than STR analysis, and uses a real-time PCR instrument which is found in most forensic and molecular biology labs.