Cytogenetic abnormalities associated with reproductive failure in Pakistani population: Experience of a tertiary care hospital.

Constitutional chromosomal abnormalities play a significant role in causing reproductive anomalies in individuals of reproductive age. With the rapid advancement of genome engineering techniques, it has now become possible to cure different genetic disorders. However, very limited data is available regarding the prevalence of such aberrations in the Pakistani population. Considering this factor, this retrospective analysis was undertaken to elucidate the type and prevalence rate of such abnormalities in our population. A total of 241 individuals, who were referred to the Liaquat National Hospital, from January 2017 to December 2021, with a history of infertility or miscarriages, were evaluated using the standard GTG banding technique. The results revealed a notably high percentage 44(18.2%) of chromosomal abnormalities in our population. Surprisingly, the frequency of these anomalies was observed to be higher in males than in females. However, further research is needed using a larger sample size to confirm the findings of this investigation.

Novel and recurrent LDLR gene mutations in Pakistani hypercholesterolemia patients.

The majority of patients with the autosomal dominant disorder familial hypercholesterolemia (FH) carry novel mutations in the low density lipoprotein receptor (LDLR) that is involved in cholesterol regulation. In different populations the spectrum of mutations identified is quite different and to date there have been only a few reports of the spectrum of mutations in FH patients from Pakistan. In order to identify the causative LDLR variants the gene was sequenced in a Pakistani FH family, while high resolution melting analysis followed by sequencing was performed in a panel of 27 unrelated sporadic hypercholesterolemia patients. In the family a novel missense variant (c.1916T > G, p.(V639G)) in exon 13 of LDLR was identified in the proband. The segregation of the identified nucleotide change in the family and carrier status screening in a group of 100 healthy subjects was done using restriction fragment length polymorphism analysis. All affected members of the FH family carried the variant and none of the non-affected members nor any of the healthy subjects. In one of the sporadic cases, two sequence changes were detected in exon 9, one of these was a recurrent missense variant (c.1211C > T; p.T404I), while the other was a novel substitution mutation (c.1214 A > C; N405T). In order to define the allelic status of this double heterozygous individual, PCR amplified fragments were cloned and sequenced, which identified that both changes occurred on the same allele. In silico tools (PolyPhen and SIFT) were used to predict the effect of the variants on the protein structure, which predicted both of these variants to have deleterious effect. These findings support the view that there will be a novel spectrum of mutations causing FH in patients with hypercholesterolaemia from Pakistan.

Sporadic Early Onset Colorectal Cancer in Pakistan: a Case- Control Analysis of Microsatellite Instability.

BACKGROUND: Early onset sporadic colorectal cancer (CRC) is a biologically and clinically distinct entity hypothesized to exhibit differences in histological features and microsatellite instability (MSI) as compared to typical onset CRC. This study compared the MSI status, mismatch repair enzyme deficiency and clinicopathological features of early onset (aged ≤45 years) with controls (>45 years). MATERIALS AND METHODS: A total of 30 cases and 30 controls were analyzed for MSI status using the Bethesda marker panel. Using antibodies against hMLH1, hMSH2 and hMSH6, mismatch repair protein expression was assessed by immunohistochemistry. Molecular characteristics were correlated with clinicopathological features. RESULTS: The early onset sporadic CRCs were significantly more poorly differentiated tumors, with higher N2 nodal involvement and greater frequency of signet ring phenotype than the typical onset cases. MSI was observed in 18/30 cases, with 12/18 designated as MSI-high (MSI-H) and 6/18 designated as MSI-low (MSI-L). In the control group, 14 patients exhibited MSI, with 7 MSI-H and 7 MSI-L. MSI tumors in both cases and controls exhibited loss of hMLH1, hMSH2 and hMSH6. MSS tumors did not exhibit loss of expression of MMR proteins, except hMLH1 protein in 3 controls. No statistically significant difference was noted in MSI status or expression of MMR proteins in cases versus controls. CONCLUSIONS: Microsatellite status is comparable between early and typical onset sporadic CRC patients in Pakistan suggesting that differences in clinicopathological features between these two subsets are attributable to other molecular mechanisms.

Clinical features and outcome of sporadic colorectal carcinoma in young patients: a cross-sectional analysis from a developing country.

Background. Early onset colorectal carcinoma (CRC) is rare and has been hypothesized to be a biologically and clinically distinct entity personifying aggressive disease and worse survival. Methods. Data for 131 patients was collected by retrospective chart review. Cox proportional hazard model was used to compute prevalence ratios and 95% confidence intervals. Results. Early onset sporadic CRC accounted for 32% of all CRC treated in the specified time period. The mean age was 33.3 ± 7.9 years and the male to female ratio was 2 : 1. Colon and rectal cancers accounted for 55% and 45% of patients, respectively. 96% of rectal carcinoma patients received appropriate therapy as opposed to 65% of colon cancers. On multivariable analysis, appropriate reception of therapy (PR 4.99; 95% CI, 1.21-20.6) and signet ring morphology (PR 2.40; 95% CI, 1.33-4.32) were significantly associated with rectal cancers as opposed to colon cancer. Kaplan-Meier analysis revealed a trend towards inferior survival for rectal carcinoma 2 years after diagnosis. Conclusion.A high prevalence of early onset CRC was noted in the study. A trend towards inferior survival was seen in patients with rectal cancer. This finding raises the possibility of rectal carcinoma being an aggressive subset of young CRC.