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Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are X-linked recessive, inherited neuromuscular disorders, caused by pathogenic variants in the dystrophin gene that encodes the dystrophin protein. A number of mutations have been identified in the past years, producing dystrophin diversity and resulting in mild to severe phenotypes in patients. Mutations in the dystrophin gene can be characterized by laboratory testing to confirm a clinical diagnosis of DMD/BMD. Traditional genetic diagnostic strategy for DMD/BMD involves the initial detection of large mutations, followed by the detection of smaller mutations, where two or more analytical methods are employed. With the development of next generation sequencing (NGS) technology, comprehensive mutational screening for all variant types can be performed on a single platform in patients and carriers, although further optimization and validation are required. Furthermore, the discovery of cell-free fetal DNA (cffDNA) in maternal plasma provides basis for noninvasive prenatal diagnosis of DMD/BMD. Here, we discuss the correlation between genotype and phenotype, the current methods of molecular genetic testing and genetic diagnostic strategy for probands and female carriers of DMD/BMD, the diagnostic ability of a comprehensive targeted NGS strategy and the possibility of it replacing conventional methods.

Background The emergence of Zika virus demands accurate laboratory diagnostics. Nucleic acid testing is currently the definitive method for diagnosis of Zika infection. In 2016, an external quality assurance (EQA) for assessing the quality of molecular testing of Zika virus was carried out in China. Methods A single armored RNA encapsulating a 4942-nucleotides (nt) long specific RNA sequence of Zika virus was prepared and used as positive samples. A pre-tested EQA panel, consisting of 4 negative and 6 positive samples with different concentrations of armored RNA, was distributed to 38 laboratories that perform molecular detection of Zika virus. Results A total of 39 data sets (1 laboratory used two test kits in parallel), produced by using commercial ( n = 38) or laboratory developed ( n = 1) quantitative reverse-transcriptase PCR (qRT-PCR) kits, were received. Of these, 35 (89.7%) had correct results for all 10 samples, and 4 (10.3%) reported at least 1 error (11 in total). The testing errors were all false-negatives, highlighting the need of improvements in detecting sensitivity. Conclusions The EQA reveals that the majority of participating laboratories are proficient in molecular testing of Zika virus.

Background Quantitative immunoassays to detect IgG antibodies are the most commonly used tests for diagnosing toxoplasmosis. We investigated the current state of standardization of quantitative immunoassays used to measure anti-Toxoplasma IgG levels. Methods Four fully automated immunoassays (Architect i4000ISR, Immulite 2000 Xpi, Siemens; Liaison, DiaSorin; Cobas e601, Roche) and one manual immunoassay (ELISA classic Toxo IgG, Virion Serion) were performed on the following: individual patient serum samples, the WHO international standards, control samples, and calibrators provided by 5 immunoassay manufacturers. Statistical analysis was used to illustrate the results. Results No perfect correlation (slope = 1.0) was found between any 2 assays. Large differences in anti-Toxoplasma IgG titers were observed among the 5 immunoassays using serum samples from individual patients. Using IS 01/600 as a calibrator minimized the inter-assay variability of anti-Toxoplasma IgG values Conclusions There is still significant effort needed towards standardization of anti-Toxoplasma IgG quantitative immunoassays.

Background Carcinoembryonic antigen (CEA) is one of the most widely used tumor markers worldwide. CEA immunoassays often yield different results. The objective of the present study was to investigate the current state of harmonization among CEA tests. Methods A total of 94 individual serum samples were divided into 3 subsets and measured in triplicate using 4 assays, Abbott Architect i2000SR, Beckman Access DXI800, Roche Cobas e601, and Siemens Advia Centaur XP. The standards from each manufacturer and the 1st International Reference Preparation (IRP) 73/601 of the World Health Organization were measured as unknowns in parallel with the patient samples using the 4 assays. The results of an external quality assessment (EQA) scheme for CEA were also analyzed. Results A perfect correlation was not observed between any 2 assays, and the values obtained using the 4 assays were different for the detection of 94 individual patient serum samples. No consistency was detected in the CEA results evaluated by various assays for EQA samples, individual patient samples, the standards from each manufacturer, and the WHO IRP 73/601. Conclusions Harmonization of the CEA results obtained using the 4 immunoassays has not yet been achieved.