Reyhan TAHTASAKAL, Halime DANA, Melike Kevser GUL, Esra DEMİRCİ, Elif Funda SENER
Meandros Medical and Dental Journal - 2026;27(2):303-310
Objective: Attention-deficit/hyperactivity disorder is a neurodevelopmental disorder. The combination of environmental and genetic factors plays a role in the etiology of ADHD. Caspase-3 (CASP3) is a cysteine-aspartate protease that performs apoptosis. After overexpression of hypoxia-inducible factor-1alpha (HIF1A) due to hypoxia, the cell enters apoptosis via a caspase-dependent cascade. It has been observed that the vitamin D receptor (VDR) is also fragmented and inactivated by caspases during apoptosis. This study aimed to reveal the relationship between VDR, HIF1A, and CASP3 gene expressions in ADHD. Materials and Methods: This case-control study included 80 children aged 6-14 years. The ADHD group consisted of 40 patients (15 girls and 25 boys), and the control group included 40 age- and sex-matched participants (15 girls and 25 boys) who were evaluated at the Department of Child and Adolescent Psychiatry. Peripheral blood samples were collected from all participants, and the expression levels of VDR, CASP3, and HIF1A genes were quantified using quantitative real-time PCR (qRT-PCR). Relative gene expression levels were calculated using the 2DeltaDeltaCt method, and group comparisons were performed using appropriate statistical analyses. Results: HIF1A and CASP3 expressions were significantly higher in ADHD children, but there was no appreciable change in the VDR gene expression between ADHD children and healthy participants. In addition, HIF1A and CASP3 were also found to be higher in boys with ADHD. Conclusion: Our findings provide new information to the literature to shed light on the hypoxia and apoptosis cascade in ADHD.
