According to the US Centers for Disease Control and Prevention (CDC) definition, genetic counseling is a process in which information is presented about how genetic conditions affect a patient or his/her family. A genetic counselor collects a patient’s personal and family health history to promote the family’s awareness and perception of specific genetic diseases, testing risks and advantages, disease management, and assessment of available therapeutic options. Intellectual disability (ID) and deafness are two common disabilities with considerable impacts on the quality of life of patients and their families. The present research has investigated the role of genetic counseling in the screening and prevention of deafness and ID based on the studies published in the Web of Science, PubMed, and Google Scholar databases between 2015 and 2023. Genetic counseling can be employed as an influential tool in screening, early diagnosis, and prevention of ID and deafness. Considering that many cases of ID and deafness are rooted in individual genetics, genetic counseling can help lessen the risk factors of developing these disabilities and improve the quality of individual and family life. The effect of genetic counseling, as an influential tool, on screening, early diagnosis, and prevention of ID and hearing loss is also assessed.

Background and Objective: Neural, hormonal, and mechanical factors regulate the expression of fast-twitch isoforms in developing and mature muscle fibers. The transcriptional mechanisms responsible for regulating the gene expression of myosin heavy chain types are not well understood. This study aimed to determine the effect of a single session of intense resistance exercise with glutamine supplementation on the relative expression of the alpha and IIX isoforms of the myosin heavy chain gene in male rats.
Methods: This experimental study was conducted on 30 adult male Wistar rats divided into three groups: control, intense resistance exercise (first experimental group), and fierce resistance exercise combined with glutamine supplementation (second experimental group). The exercise groups participated in a single session of resistance climbing on an inclined plane with 4 sets of 5 repetitions, 30 seconds of rest between repetitions, and 2 minutes of rest between sets. Glutamine supplement powder was dissolved in 100 ml of distilled water at a dose of 0.5 grams per kilogram of body weight and administered daily via gavage for 5 days. The expression of alpha and IIX isoforms of the myosin heavy chain gene was examined in the extensor digitorum longus muscle tissue.
Results: The relative expression of the alpha myosin heavy chain gene in the fast-twitch muscle fibers increased significantly in the first experimental group (1.93±0.298) and the second experimental group (1.65±0.195) compared to the control group (P<0.05). The relative expression of the IIX motor unit gene in the fast-twitch muscle fibers also increased significantly in the first experimental group (1.42±0.239) and the second experimental group (1.26±0.190) compared to the control group (P<0.05). The increase in the relative expression of the alpha myosin heavy chain gene in the first experimental group compared to the second experimental group was statistically significant (P<0.05). However, the increase in the relative expression of the IIX motor unit gene in the first experimental group compared to the second experimental group was not statistically significant.
Conclusion: Our study concludes that a single session of intense resistance exercise, with or without glutamine supplementation, significantly increases the relative expression of the alpha myosin heavy chain gene and the IIX motor unit gene in the fast-twitch muscle fibers of the extensor digitorum longus muscle in adult male rats. These findings provide valuable insights into the molecular