Background Polycystic ovary syndrome (PCOS) became one of the main reasons for infertility in women. It has an obvious effect on phenotype represented by hirsutism, increased body mass index, obesity, and acne, while biochemical tests show adverse hormonal imbalance with hyperandrogenism as testosterone levels increases. From molecular level point of view, pathogenic SNPs may change CAG repeats number along androgen receptor (AR) resulting in altered function of the gene causing different affinity to androgen hormones. Methods Recruiting 150 patients diagnosed with PCOS for the study, genomic DNA was extracted and amplified using specifically designed exon 1 PCR primers employing gene walking technique. The resulting amplicons were sequenced and thoroughly analyzed for polymorphism and CAG repeats number. Results Data obtained from recruiting 150 patients diagnosed with PCOS showed that sequences X:67545209–67545742; X:67545503–67545739 of exon 1 harbored 7 SNPs altered secondary structure of the resulting protein and forced toward the use of CAA as synonymous codon instead of the normal CAGs stretches. This led to produced alternative mRNA that eventually changed nonsense-mediated mRNA decay mechanism. Conclusion Probability of PCOS in women with polymorphic AR gene is higher than others, especially women with high number of CAG stretches. The new finding and highlight of this study is that alternative codon usage (CAAs) to produce the same amino acid (Gln) and compensate the reduced number of CAG repeats number may be attributed to epigenetic mechanism to mitigate the adverse effect of such change and maintain a normal function of AR gene. This finding was not previously reported in former studies.

The role of KRAS gene was investigated in manifestation of colorectal cancer in Iraqi patients. A total 40 blood samples were collected during October 2016 to January 2017 from AL-Amal Hospital in Baghdad and 20 blood samples from healthy subjects served as control. Blood samples were collected from subjects of 40-70 years old for both patients and control. The study found that age group 61-70 years old were more susceptible to colorectal cancer with ratio of 40% more than younger individuals involved in this study with higher frequency in males with 75.5% than females who show 49.5% (p>0.01) when both compared to the same gender. DNA extracted from positive cancer samples and control were subjected to specific PCR amplification using 10 specifically designed primers for this study to amplify KRAS gene exons. DNA sequencing for the resulting amplicons showed the presence of significant genetic change that included substitution and insertion, causing 15% frame shift and 85% missense changes at positions 5920, consequently led to sever disruption in KRAS function.

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A total 200 tumor samples were collected from patients suffering from colorectal CRC at Al-Amal hospital. Their ages ranged from 40 – 70 years old and distributed according to gender as 130 male and 70 female. We found that CRC was more common in male than female, and more frequent in elderly persons especially in age group of 61 – 70 years old. From 12 specifically designed primers that were able to amplify KRAS gene in those patients’ blood samples, only 2 gave a specific band when tumor sample was used. Molecular analysis of the sequence obtained from those two primers showed the presence of 83 missense mutations in both of them, 20 in the first sequence were associated with pathogenic effect on KRAS gene, 3 frame shift, and 3 insertions, while in the second sequence obtained from primer PK2 4 frame shift mutations, and 4 insertions were identified. The impact finding is that in both sequences, open reading frames (ORFs) were developed that affected cell proliferation dramatically and produced truncated functionless proteins causing KRAS to cease control over cell cycle.