Comparative study of three PCR-based copy number variant approaches, CFMSA, M-PCR, and MLPA, in 22q11.2 deletion...

Small submicroscopic DNA copy number variants represent an important source of variation in the human genome, human phenotypic diversity, and disease susceptibility. Consequently, there is a pressing need for the development of methods allowing the efficient, accurate, and cheap measurement of genomic copy number polymorphisms in clinical cohorts. The PCR-based strategies, being cost-effective and sensitive, are considered important in the development of screening techniques. PCR-based techniques such as multiplex PCR; multiplex ligation-dependent probe amplification; and a new single-tube assay technique, the competitive fluorescent multiplex STRP assay, have been applied to 22q11.2 detection, a typical example of deletion syndromes. In this study, we compared the reliability and application of these three techniques in a cohort of 17 patients affected with 22q11.2 deletion and 300 normal controls. All three techniques shared 100% sensitivity; however, the competitive fluorescent multiplex STRP assay had the lowest possibility of concurrent false-positive signals from two adjoining probes in a genomic region. Moreover, it is a relatively fast and low-cost procedure to detect the deletion of 22q11.2 in numerous patients with several minor symptoms of deletion syndromes. Multiplex PCR, a rapidly developing and cheap technique, allows detection of atypical deletions.