Genetic Aspects Of Athletic Performance: The African Runners Phenomenon.

The current dominance of African runners in long-distance running is an intriguing phenomenon that highlights the close relationship between genetics and physical performance. Many factors in the interesting interaction between genotype and phenotype (eg, high cardiorespiratory fitness, higher hemoglobin concentration, good metabolic efficiency, muscle fiber composition, enzyme profile, diet, altitude training, and psychological aspects) have been proposed in the attempt to explain the extraordinary success of these runners. Increasing evidence shows that genetics may be a determining factor in physical and athletic performance. But, could this also be true for African long-distance runners? Based on this question, this brief review proposed the role of genetic factors (mitochondrial deoxyribonucleic acid, the Y chromosome, and the angiotensin-converting enzyme and the alpha-actinin-3 genes) in the amazing athletic performance observed in African runners, especially the Kenyans and Ethiopians, despite their environmental constraints.

Pyrimidine-5'-nucleotidase Campinas, A New Mutation (p.r56g) In The Nt5c3 Gene Associated With Pyrimidine-5'-nucleotidase Type I Deficiency And Influence Of Gilbert's Syndrome On Clinical Expression.

Pyrimidine-5'-nucleotidase type I (P5'NI) deficiency is an autosomal recessive condition that causes nonspherocytic hemolytic anemia, characterized by marked basophilic stippling and pyrimidine nucleotide accumulation in erythrocytes. We herein present two African descendant patients, father and daughter, with P5'N deficiency, both born from first cousins. Investigation of the promoter polymorphism of the uridine diphospho glucuronosyl transferase 1A (UGT1A) gene revealed that the father was homozygous for the allele (TA7) and the daughter heterozygous (TA6/TA7). P5'NI gene (NT5C3) gene sequencing revealed a further change in homozygosity at amino acid position 56 (p.R56G), located in a highly conserved region. Both patients developed gallstones; however the father, who had undergone surgery for the removal of stones, had extremely severe intrahepatic cholestasis and, liver biopsy revealed fibrosis and siderosis grade III, leading us to believe that the homozygosity of the UGT1A polymorphism was responsible for the more severe clinical features in the father. Moreover, our results show how the clinical expression of hemolytic anemia is influenced by epistatic factors and we describe a new mutation in the P5'N gene associated with enzyme deficiency, iron overload, and severe gallstone formation. To our knowledge, this is the first description of P5'N deficiency in South Americans.