Molecular diagnosis for Duchenne and Becker muscular dystrophies (DMD/BMD) involves a two-tiered approach for detection of deletions/duplications using MLPA or array CGH, followed by sequencing of coding and flanking intronic regions to detect sequence variants, which is time-consuming and expensive. We have developed a comprehensive next-generation sequencing (NGS)-based single-step assay to sequence the entire 2.2 Mb of the DMD gene to detect all copy number and sequence variants in both index males and carrier females. Assay validation was 100% concordant with other methodologies. A total of 772 samples have been tested, of which 62% (N = 480) were index cases with a clinical suspicion of DMD. Carrier testing females account for 38% (N = 292). Molecular diagnosis was confirmed in 86% (N = 413) of the index cases. Intragenic deletions and duplications (single-exon or multi-exon) were detected in 60% (N = 247) and 14% (N = 58) of the index cases, respectively. Full-sequence analysis of the entire gene allows for detection of deep intronic pathogenic variants and accurate breakpoint detection of CNVs involving similar exons, which could have an impact on the outcome of clinical trials. This comprehensive assay is highly sensitive for diagnostic testing for DMD and is also suitable for confirmatory testing for newborn screening for DMD.

Mercury is a heavy metal toxicant that is prevalent throughout the environment. Organic forms of mercury, such as methylmercury (MeHg), can cross the placenta and can lead to lasting detrimental effects in the fetus. The toxicological effects of MeHg on the placenta itself have not been clearly defined. Therefore, the purpose of the current study was to assess the transport of MeHg into placental syncytiotrophoblasts and to characterize the mechanisms by which MeHg exerts its toxic effects. Cultured placental syncytiotrophoblasts (BeWo) were used for these studies. The transport of radioactive MeHg was measured to identify potential mechanisms involved in the uptake of this compound. The toxicological effects of MeHg on BeWo cells were determined by assessing visible pathological change, autophagy, mitochondrial viability, and oxidative stress. The findings of this study suggest that MeHg compounds are transported into BeWo cells primarily by sodium-independent amino acid carriers and organic anion transporters. The MeHg altered mitochondrial function and viability, decreased mitophagy and autophagy, and increased oxidative stress. Exposure to higher concentrations of MeHg inhibited the ability of cells to protect against MeHg-induced injury. The findings show that MeHg is directly toxic to syncytiotrophoblasts and may lead to disruptions in the fetal/maternal transfer of nutrients and wastes.