Alpha-Actinin-3 R577X Polymorphism Influences Muscle Damage and Hormonal Responses After a Soccer Game.

Coelho, DB, Pimenta, EM, Rosse, IC, Veneroso, C, Pussieldi, GDA, Becker, LK, De Oliveira, EC, Carvalho, MRS, and Silami-Garcia, E. Alpha-actinin-3 R577X polymorphism influences muscle damage and hormonal responses after a soccer game. J Strength Cond Res 33(10): 2655-2664, 2019-The purpose of this study was to evaluate indicators of muscle damage and hormonal responses after soccer matches and its relation to alpha-actinin-3 (ACTN3) gene expression (XX vs. RR/RX), considering that the R allele produces alpha-actinin-3 and provides greater muscle strength and power. Thirty players (10 XX and 20 RR/RX) younger than 16 years were evaluated in this study. Blood samples were collected immediately before, after, 2, and 4 hours after the games to assess muscle damage (creatine kinase [CK] and alpha-actin) and hormonal responses (interleukin-6 [IL-6], cortisol, and testosterone). Postgame CK was higher as compared to the pregame values in both groups and it was also higher in the RR/RX (p < 0.05) than in the XX. The concentrations of alpha-actin and IL-6 were similar for both groups and did not change over time. Testosterone was increased after the game only in the RR/RX group (p < 0.05). Cortisol concentrations in group RR/RX were higher immediately after the game than before the game, and 2 and 4 hours after the game the concentration decreased (p < 0.05). The RR and RX individuals presented higher markers of muscle microtrauma and hormonal stress, probably because they performed more speed and power actions during the game, which is a self-regulated activity. From the different responses presented by RR/RX and XX genotypes, we conclude that the genotypic profile should be taken into account when planning training workloads and recovery of athletes.

Correction: Biotinidase deficiency: Genotype-biochemical phenotype association in Brazilian patients.

[This corrects the article DOI: 10.1371/journal.pone.0177503.].

Impaired acuity of the approximate number system in 22q11.2 microdeletion syndrome

A magnitude comparison deficit has been frequently observed in velocardiofacial syndrome (Del22q11.2). We hypothesized that this deficit extends to impairments in the acuity of the approximate number system (ANS). Three groups of children aged 8-14 years were investigated: Del22q11.2 children (n = 12), low cognitive ability children (LCA; n = 12), and matched typically developing children (TD; n = 28). All children were assessed with a simple reaction time task and symbolic and nonsymbolic number comparison tasks. To estimate the acuity of the ANS, the Weber fraction (w) was calculated from the nonsymbolic comparison task. The Del22q11.2 group exhibited a significantly higher w compared with the other groups. Importantly, no significant differences were found in w between the TD and LCA groups. The performance pattern of the Del22q11.2 group was similar to the TD group in the symbolic comparison task, and both of these groups had better performance than the LCA group. The impairment of ANS acuity observed in individuals with Del22q11.2 cannot be explained by deficits in general processing speed because no significant group differences were found in the simple reaction time task. These results suggest that lower acuity of the ANS should be added to the behavioral phenotype of Del22q11.2. The absence of impaired ANS acuity in the LCA group is consistent with the hypothesis that number sense is a relatively specific and autonomous domain. Investigations of low ANS acuity in mathematics learning difficulties and Del22q11.2 should be intensified...

Impaired acuity of the approximate number system in 22q11.2 microdeletion syndrome

A magnitude comparison deficit has been frequently observed in velocardiofacial syndrome (Del22q11.2). We hypothesized that this deficit extends to impairments in the acuity of the approximate number system (ANS). Three groups of children aged 8-14 years were investigated: Del22q11.2 children (n = 12), low cognitive ability children (LCA; n = 12), and matched typically developing children (TD; n = 28). All children were assessed with a simple reaction time task and symbolic and nonsymbolic number comparison tasks. To estimate the acuity of the ANS, the Weber fraction (w) was calculated from the nonsymbolic comparison task. The Del22q11.2 group exhibited a significantly higher w compared with the other groups. Importantly, no significant differences were found in w between the TD and LCA groups. The performance pattern of the Del22q11.2 group was similar to the TD group in the symbolic comparison task, and both of these groups had better performance than the LCA group. The impairment of ANS acuity observed in individuals with Del22q11.2 cannot be explained by deficits in general processing speed because no significant group differences were found in the simple reaction time task. These results suggest that lower acuity of the ANS should be added to the behavioral phenotype of Del22q11.2. The absence of impaired ANS acuity in the LCA group is consistent with the hypothesis that number sense is a relatively specific and autonomous domain. Investigations of low ANS acuity in mathematics learning difficulties and Del22q11.2 should be intensified.(AU)

Count on dopamine: influences of COMT polymorphisms on numerical cognition.

Catechol-O-methyltransferase (COMT) is an enzyme that is particularly important for the metabolism of dopamine. Functional polymorphisms of COMT have been implicated in working memory and numerical cognition. This is an exploratory study that aims at investigating associations between COMT polymorphisms, working memory, and numerical cognition. Elementary school children from 2th to 6th grades were divided into two groups according to their COMT val158met polymorphism [homozygous for valine allele (n = 61) vs. heterozygous plus methionine homozygous children or met+ group (n = 94)]. Both groups were matched for age and intelligence. Working memory was assessed through digit span and Corsi blocks. Symbolic numerical processing was assessed through transcoding and single-digit word problem tasks. Non-symbolic magnitude comparison and estimation tasks were used to assess number sense. Between-group differences were found in symbolic and non-symbolic numerical tasks, but not in working memory tasks. Children in the met+ group showed better performance in all numerical tasks while val homozygous children presented slower development of non-symbolic magnitude representations. These results suggest COMT-related dopaminergic modulation may be related not only to working memory, as found in previous studies, but also to the development of magnitude processing and magnitude representations.

Effect of ACTN3 gene on strength and endurance in soccer players.

Sports efficiency in activities in which strength and speed are the determining factors has been associated to the ACTN3 gene, which is responsible for the expression of α-actinin-3. Soccer is a mainly aerobic sport because of its long duration, but the acute actions that define the game demand a lot of strength and speed. The purpose of the present study was to compare the performance capacity of soccer players with different genotype groups of ACTN3 (XX, RX, and RR) in strength, speed, and endurance tests. Two hundred professional players of Brazilian soccer first division teams participated in this study. Speed, jump, and endurance test results were compared with the polymorphisms of the ACTN3 gene. It was noticed that RR individuals spent less time to run a 10-m path, compared with XX individuals (p < 0.05). The RR individuals also presented lower time rates at the 20- and 30-m path, compared with RX and XX individuals (p < 0.05). In jump tests, RR individuals presented higher rates, compared with RX and XX individuals (p < 0.05). As for aerobic tests, the XX individuals presented higher rates of V[Combining Dot Above]O2 max, compared with the RR group (p < 0.05), and did not differ from the RX group. The main conclusion of this study is that soccer players of genotype ACTN3/RR are the fastest in short distances and present higher jump potential. ACTN3/XX individuals presented the highest aerobic capacity. These findings can be used in training load adjustment and can influence the development of tactical schemes in soccer matches.