Different Associations Between CDKAL1 Variants and Type 2 Diabetes Mellitus Susceptibility: A Meta-analysis

Identification of genetic risk variants for Type-2 Diabetes mellitus in Pakistani Pashtun population: A case-control association study

Background and Objective

Pakistan, a South Asian developing country, is experiencing a rapid increase in number of diabetes cases. High prevalence ratio of diabetes in Pakistani population and lack of genetic research studies prompted us to design this study. This present study investigated Pakistani Pashtun population for (known and novel SNPs) and its possible correlation with Type-2 Diabetes Mellitus (T2DM).

Methods

This two stage (discovery & validation stage), case-control association study included one thousand individuals (Patients with T2DM=500 & controls=500) from eight districts of Khyber Pakhtunkhwa Pakistan. The study duration/period was from March 2018 to January 2020. In the first stage (the discovery stage) the target population was screened for known and novel T2DM-associated genetic markers. In the validation stage, identified variants were confirmed for T2DM association using MassARRAY genotyping and association analysis.

Results

Exome sequencing detected eleven known and four novel/new genetic markers in the study population. Novel variants were preferred over the known for follow-up analysis/validation. Among the identified variants strong associations were confirmed for the following variants; rs1781133/ANKRD65 (OR=2.10, 95%Cl=1.06-3.08, P=0.003) rs2274791/TTLL10 (OR=1.97, 95%Cl=1.36-2.62, P=0.025), rs71628928/RNF223 (OR=1.82, 95%Cl=0.97-1.92, P=0.041), and rs609805/SCNN1D (OR=2.21, 95%Cl=1.92-3.09, P=0.001) with T2DM; other reported variants showed no noticeable association (having P>0.05) with T2DM.

Conclusion

This study reports new genetic risk variants for T2DM in Pashtun population providing valuable insights into the genetic basis of T2DM in this group.

Genetic and inflammatory factors underlying gestational diabetes mellitus: a review

Gestational diabetes mellitus (GDM) poses a significant global health concern, impacting both maternal and fetal well-being. Early detection and treatment are imperative to mitigate adverse outcomes during pregnancy. This review delves into the pivotal role of insulin function and the influence of genetic variants, including SLC30A8, CDKAL1, TCF7L2, IRS1, and GCK, in GDM development. These genetic variations affect beta-cell function and insulin activity in crucial tissues, such as muscle, disrupting glucose regulation during pregnancy. We propose a hypothesis that this variation may disrupt zinc transport, consequently impairing insulin production and secretion, thereby contributing to GDM onset. Furthermore, we discussed the involvement of inflammatory pathways, such as TNF-alpha and IL-6, in predisposing individuals to GDM. Genetic modulation of these pathways may exacerbate glucose metabolism dysregulation observed in GDM patients. We also discussed how GDM affects cardiovascular disease (CVD) through a direct correlation between pregnancy and cardiometabolic function, increasing atherosclerosis, decreased vascular function, dyslipidemia, and hypertension in women with GDM history. However, further research is imperative to unravel the intricate interplay between inflammatory pathways, genetics, and GDM. This understanding is pivotal for devising targeted gene therapies and pharmacological interventions to rectify genetic variations in SLC30A8, CDKAL1, TCF7L2, IRS1, GCK, and other pertinent genes. Ultimately, this review offers insights into the pathophysiological mechanisms of GDM, providing a foundation for developing strategies to mitigate its impact.

Shared Genetics between Age at Menarche and Type 2 Diabetes Mellitus: Genome-Wide Genetic Correlation Study

Background: Age at menarche (AAM) has been associated with type 2 diabetes mellitus (T2DM). However, little is known about their shared heritability. Methods: Our data comes from the Taiwan Biobank. Genome-wide association studies (GWASs) were conducted to identify single-nucleotide polymorphisms (SNPs) related to AAM-, T2DM-, and T2DM-related phenotypes, such as body fat percentage (BFP), fasting blood glucose (FBG), and hemoglobin A1C (HbA1C). Further, the conditional false discovery rate (cFDR) method was applied to examine the shared genetic signals. Results: Conditioning on AAM, Quantile-quantile plots showed an earlier departure from the diagonal line among SNPs associated with BFP and FBG, indicating pleiotropic enrichments among AAM and these traits. Further, the cFDR analysis found 39 independent pleiotropic loci that may underlie the AAM-T2DM association. Among them, FN3KRP rs1046896 (cFDR = 6.84 × 10-49), CDKAL1 rs2206734 (cFDR = 6.48 × 10-10), B3GNTL1 rs58431774 (cFDR = 2.95 × 10-10), G6PC2 rs1402837 (cFDR = 1.82 × 10-8), and KCNQ1 rs60808706 (cFDR = 9.49 × 10-8) were highlighted for their significant genetic enrichment. The protein-protein interaction analysis revealed a significantly enriched network among novel discovered genes that were mostly found to be involved in the insulin and glucagon signaling pathways. Conclusions: Our study highlights potential pleiotropic effects across AAM and T2DM. This may shed light on identifying the genetic causes of T2DM.