Tehran University Medical Journal

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Background: A balanced reciprocal translocation is a structural abnormality, which at least consist of breakage of two non-homologous chromosomes along with pieces exchange and form quadrivalant structure that can produce unbalanced chromosomes during meiosis I and result in a fetus abortion. The aim of the present study is to offer using preimplantation genetic diagnosis (PGD) 24sure array, which delivers aneuploidy screening of 24 chromosomes, within a few hours to increase fertility and bearing a child without chromosomal abnormality of this couple. This technique could replace embryo donation for child bearing of this couple. Case presentation: A young couple with recurrent pregnancy loss in 6th and 7th week of pregnancy without family history of recurrent miscarriage and any clinical signs had conferred. All laboratory tests including hormonal, infections, semen and hysterosalpingography were normal except karyotype that showed balanced reciprocal translocation between chromosomes 5 and 18 in male. Chromosomal study of male parents showed normal karyotype. Conclusion: A balanced reciprocal translocation carrier is phenotypically normal, but during meiosis І, carrier chromosomes cant pair normally and form quadrivalant instead of bivalant that depend on type of their segregation (alternate, adjacent 1, adjacent 2,3:1,4:0), produce gametes that are chromosomally unbalanced which can result in early fetus abortion. Considering the number of abnormal gametes, the most effective way to help couples with this problem seems to be PGD 24sure, since it can identify reciprocal and Robertsonian translocation and allows concurrent screening of all chromosomes for aneuploidy. Another technique that can be compared with PGD 24sure is fluorescence in situ hybridization (FISH), but it has several technical limitations such as it is expensive and complexity, in addition it has only few probes (for chromosomes 21, 13, 18, X, Y) so sometimes necessary to create patient specific protocols.

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Background: Colorectal cancer is the third most common cancer in the world. Non-coding RNA especially miRNAs have important regulatory roles in cancer. miRNAs are small non coding RNA 21-23 nucleotides long which have different levels of expression between tumors and normal tissues. This study was designed to compare expression level of miRNA-21 between Iranian population colorectal cancer tissues and normal tissue. Methods: This case-control study has performed in medical genetics department of Tehran University of Medical Sciences from January to November 2013. We used 35 samples. The samples were isolated from tumor and adjacent normal tissues of colon. Thirty-five samples were divided into different groups according to cliniopathologic features including tumor size (>4 and <4 cm), metastasis (+ and -) and stage. After small RNA extraction from tissues by small RNA purification kit the quality and quan-tity of extracted RNA was determined using spectrophotometry. cDNAs were synthe-sized and real-time polymerase chain reaction carried out. Finally expression levels were statistically analyzed by LinRegPCR and REST software. Results: miRNA-21 expression ratio in stages I, II and III were 1/804 and 4/574, re-spectively, the increase from stage III was statistically significant (P= 0.037). The ex-pression were also studied according to different clinicopathologic status of colon can-cer, tumor size (>4 and <4 cm) and metastatic (+ and -), miRNA-21 over expressed in both groups, however the increase was not statistically significant. Conclusion: In this study, we found miR-21 over-expression in advanced stage in tu-moral tissue comparing with normal adjacent tissue. This means perhaps in the future it would be possible to use miRNA-21 as an informative prognostic biomarker to guide for better treatment strategies for colorectal cancer patients. Our findings also indicate that miRNA-21 is a promising new molecular target for designing novel therapeutic strategies to control colorectal cancer.