Effect of ACE (I/D) and ACTN-3 (R/X) Genotypes on some Factors of Physical Fitness and Performance of Motor Skills in 6-8-Year-Old Children

Introduction: The identification of the factors affecting the physical performance and development of childrenchr('39')s motor skills can be of great importance in participating in physical activities, preventing overweight and obesity, as well as identifying and guiding the top talented children in sport. Therefore, this study aimed to investigate the effect of different ACE (I/D) and ACTN-3 (R/X) genotypes on some factors of physical fitness and motor skill performance in children.   Materials & Methods: The statistical population of this study included 6-8-year-old school children in Tehran, Iran. In total, 50 cases were selected randomly using the cluster-sampling method. The data were collected using the Physical Fitness Test, Test of Gross Motor Development-Third Edition (TGMD-3), and PCR for the determination of ACE and ACTN-3 polymorphism. Furthermore, a one-way analysis of variance and independent t-test were used to analyze the study data. A p-value less than 0.05 was considered statistically significant. Ethics code: IR.KHU.REC.1399.010     Findings: The results showed that children carrying allele D of ACE gene, (DD or ID genotype), compared to those with II genotype (P<0.05), and the cases carrying the allele R of ACTN-3 gene (RR or RX genotype), compared to those with XX genotype (P<0.05) had more muscular strength in hand and foot, as well as higher levels of locomotor skills. However, no significant difference was observed regarding the performance of ball motor skills (P>0.05).   Discussions & Conclusions: According to the results of the study, it can be said that the children carrying DD or ID genotype of ACE and RR or RX genotype of ACTN-3 had a higher level of physical development and consequently higher levels of locomotor skill performance. Therefore, if they are provided with desirable environmental conditions, they will be able to do sport skills accompanied by higher levels of performance.