An efficient trio-based mini-haplotyping method for genetic diagnosis of phenylketonuria

Objective: The phenylalanine hydroxylase (PAH) locus has high linkage disequilibrium. Haplotypes related to this locus may thus be considered sufficiently informative for genetic diagnosis and carrier screening using multi-allelic markers. In this study, we present an efficient method for haplotype analysis of PAH locus using multiplexing dyes. In addition, we explain how to resolve the dye shift challenge in multiplex short tandem repeat (STR) genotyping. Materials and Methods: One hundred family trios were included in this descriptive study. The forward primer of a tetra-nucleotide STR and the reverse primer of a variable number tandem repeat (VNTR) were labeled with three different non-overlapping dyes 5-carboxyfluorescein (FAM), 6-carboxy-N,N,N�,N�-tetramethylrhodamine (HEX) and 6-carboxy-N,N,N�,N�-tetramethylrhodamine (TAMRA). The polymerase chain reaction (PCR) products from each family trio were multiplexed for capillary electrophoresis and results were analyzed using Peak Scanner software. Results: Multiplexing trio products decreased the cost significantly. The TAMRA labeled products had a significant predictable shift (migrated at a slower electrophoretic rate) relative to the HEX and FAM labeled products. Through our methodology we achieve, the less inter-dye shift than intra-dye shift variance. Correcting the dye shift in the labeled products, according to the reference allele size, significantly decreased the inter-dye variability (P<0.001). Conclusion: Multiplexing trio products helps to detect and resolve the dye shift accurately in each family, which otherwise would result in diagnostic error. The dye system of FAM, HEX and TAMRA is more feasible and cheaper than other dye systems

Comparable vitamin D3 metabolism in the endometrium of patients with recurrent spontaneous abortion and fertile controls

Vitamin D exerts important roles during pregnancy, and its deficiency may be associated with several pregnancy complications, including pregnancy loss, yet no data are available for molecules involved in vitamin D metabolism in patients with unexplained recurrent spontaneous abortion. In this study, we investigated possible difference in endometrial expression of vitamin D3 receptor (VDR), 1α-hydroxylase (CYP27B1), and 24-hydroxylase (CYP24A1) in women with recurrent spontaneous abortion (n=8) and healthy controls (n=8). Gene expression of VDR, CYP27B1, and CYP24A1 was determined by real-time PCR, while VDR and CYP27B1 proteins were localized by immunohistochemistry and their abundance was validated by Western blot. We found that both patient and control groups expressed comparable levels of endometrial VDR, CYP27B1, and CYP24A1 transcripts. In line with the gene-expression results, CYP27B1 and different isoforms of VDR protein were present at the same abundance in the endometria of both groups. No significant alteration in VDR and CYP27B1 immunoreactivity pattern was found in the endometrium of patients compared to fertile controls, however. The results of the present study, therefore, do not support the hypothesis of differential expression of key molecules involved in vitamin D3 metabolism in the endometrium of recurrent spontaneous abortion patients and fertile controls. © 2015 Wiley Periodicals, Inc.