Background/Objectives: The variability of the internal acoustic meatus (IAM) and its morphological peculiarities are of high clinical significance in otologic interventions and neurosurgery. Considering the complexity of the neurovascular structures housed by the IAM, including passage of the facial nerve, the aim of the study was to highlight the morphological peculiarities of the IAM and their clinical significance. Methods: The age peculiarities of the IAM course were studied on 18 serially, transversely sectioned human embryos and fetuses, as well as on 20 newborn and 20 adult formalin-fixed hemiheads. The morphometric parameters of the IAM (width, height, length, and angles between the anterior and posterior walls of the IAM and the longitudinal axis of the petrous ridge (LAPR) were evaluated on 82 dry temporal bones. Results: In embryos and early fetal stages of development, the course of the IAM formed an acute, posteromedially open angle with the longitudinal axis of the petrous part of the temporal bone (LAP); in newborns, it was a right angle; in adults, it was an acute, anteromedially open angle. Various shapes of the IAO, such as oval (51.2%), semioval (23.2%), quadrangular (13.4%), heart-like (3.7%), and triangular (8.5%), were highlighted. The mean width of the internal acoustic opening (IAO) was 7.7 ± 2.11 mm (right/left—8.2 ± 2.22 mm/7.2 ± 1.89 mm), with a statistically significant difference (p = 0.031). The mean height of the IAO was 5.3 ± 1.43 mm (right/left—5.6 ± 1.58 mm/5.0 ± 1.22 mm), p = 0.082. The mean length of the IAM was 10.1 ± 2.83 (right/left—10.5 ± 2.96 mm/9.7 ± 2.67 mm), p = 0.214. A partial septum was revealed in 3.6% of cases, while total septation of the IAM was observed in 2.4%. The mean angle between the anterior wall of the IAM and the longitudinal axis of the petrous ridge (AWIAM/LAPR) was 21.4 ± 13.67° (right/left—22.2 ± 14.62°/20.5 ± 12.78°), p = 0.564. The mean angle between the posterior wall of the IAM and the longitudinal axis of the petrous ridge (PWIAM/LAPR) was 82.4 ± 8.02° (right/left—84.3 ± 7.93°/80.5 ± 7.76°); p = 0.032. Conclusions: In the initial stages of an individual’s ontogenesis, the IAM forms an acute, posteromedially open angle with the LAP; in newborns—a right angle; in adults—an acute, anteromedially open angle. Both morphological characteristics and morphometric parameters of the IAO and IAM vary bilaterally. The oval, semioval, quadrangular, heart-like, and triangular shapes of the IAO were highlighted. Partial and total septation of the IAM were revealed. Only the TDAIO and PWIAM/LAPR angle were statistically significant, p < 0.05, while the bilateral correlation was negligible. The established morphological variants of the IAM could predispose to facial and vestibulocochlear nerve impairments.

Genetic testing for common adult diseases, such as chronic multifactorial conditions like type 2 diabetes, cardiovascular diseases, cancer, neurodegenerative disorders, and autoimmune diseases, enables individual risk assessment, early identification of predisposed individuals, and optimization of prevention or treatment strategies. Aim: To synthesize data on available genetic tests for major categories of common adult diseases, with relevant examples, indications, and limits. Materials and methods: We analyzed scientific literature published between 2015 and 2025, including narrative reviews, systematic reviews, observational studies, and clinical guidelines. Results: Genetic testing for common adult diseases primarily relies on polygenic risk scores (PRS), SNP genotyping, or targeted panels. Genetic testing is conducted within specialized genetic consultations and is recommended in specific clinical contexts: early disease onset (e.g., cancer before age 50), positive family history across multiple generations, atypical clinical presentations, therapeutic indications (e.g., pharmacogenomics), and reproductive counseling. In each case, genetic testing has specific indications and limitations. Limitations arise from incomplete gene penetrance, meaning not all individuals with a pathogenic variant develop the disease; no single genetic mutation fully determines risk; and variability in gene expression, where individuals with the same mutation may exhibit different clinical forms. Epigenetic and environmental factors also influence risk. Conclusions: 1. Common adult diseases result from complex interactions between genes, epigenetics, and the environment. 2. Genetic tests offer opportunities for prevention, diagnosis, and personalized treatment, with clinical utility varying by disease. 3. The limitations of genetic testing stem from the etiological complexity of multifactorial diseases, requiring genetic counseling for result interpretation and communication.