Association of IGF-I Gene Polymorphism with Blood Concentration of IGF-I, Body Composition, Bone Age and Response to Combined Exercise Program in Teen-Aged Children / 대한스포츠의학회지

Association of insulin like growth factor (IGF)-I gene polymorphism with blood concentration of IGF-I, body composition, bone age and response to combined exercise program in teen-aged children. The purpose of this study was to determine whether there are the differences of blood concentration of IGF-I, body composition, bone age and response to combined exercise program according to IGF-I gene polymorphism in Korean teen-aged children. Subjects were recruited by 143 teen-aged children (male: 78, female: 65) from elementary school. Twelve weeks exercise program was consisted of resistance training and aerobic exercise. For the comparison of items and responses to combined exercise program according to IGF-I gene polymorphism, blood concentration of IGF-I, skinfold thickness, body circumferences, and growth markers were measured at baseline and after intervention. Body weight, %fat, BMI, skinfold thickness, circumferences, blood concentration of IGF-I, and bone age showed no significant differences following to IGF-I gene polymorphism. Although body composition and blood concentration of IGF-I showed a positive change after 12 week exercise training, 12 week exercise-mediated changes of body composition and blood concentration of IGF-I showed no significant differences following to IGF-I gene polymorphism. In conclusion, IGF-I gene polymorphism no contributed to the differences of body composition, blood concentration of IGF-I, and 12 week exercise-mediated these changes in teen-aged children.

Association of IGF-I gene polymorphisms with milk yield and body size in Chinese dairy goats

The association of IGF-I gene polymorphisms with certain traits in 708 individuals of two Chinese dairy-goat breeds (Guanzhong and Xinong Saanen) was investigated. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and DNA sequencing methods were employed in screening for genetic variation. Two novel mutations were detected in the 5'-flanking region and in intron 4 of IGF-I gene, viz., g.1617 G > A and g.5752 G > C (accession D26119.2), respectively. The associations of the g.1617 G > A mutation with milk yield and the body size were not significant (p > 0.05). However, in the case of g.5752 G > C, Xinong Saanen dairy goats with the CG genotype presented longer bodies (p < 0.05). Chest circumference (p < 0.05) was larger in Guanzhong goats with the GG genotype. In Xinong Saanen dairy goats with the CC genotype, milk yields were significantly higher during the first and second lactations (p < 0.05). Hence, the g.5752 G > C mutation could facilitate association analysis and serve as a genetic marker for Chinese dairy-goat breeding and genetics.

Analysis of cytosine adenine repeat polymorphism of the IGF-I promoter gene in children with idiopathic short stature / 소아과

PURPOSE: A polymorphism in the IGF-I gene promoter region is known to be associated with serum IGF-I levels, birth weight, and body length, suggesting that IGF-I gene polymorphism might influence postnatal growth. The present study aimed to investigate the role of this polymorphic cytosine-adenine (CA) repeat of the IGF-I gene in children with idiopathic short stature. METHODS: The study involved 131 children (72 boys and 59 girls) diagnosed with idiopathic short stature, aged 7-15 years. Genomic DNA was extracted from anticoagulated peripheral whole blood. The primers were designed to cover the promoter region containing the polymorphic CA repeat. Data were analyzed using GeneMapper software. The correlations between age and serum IGF-I levels were analyzed using Spearmans correlation coefficient. RESULTS: The CA repeat sequences ranged from 15 to 22 , with 19 CA repeats the most common with an allele frequency of 40.6%. Homozygous for 19 CA repeat was 13.0%, heterozygous for 19 CA repeat was 56.5%, and 19 CA non-carrier was 30.5%. The three different genotype groups showed no significant differences in height, body weight and body mass index, and serum IGF-I levels. The serum IGF-I level and age according to the IGF-I genotypes were significantly correlated in the entire group, 19 CA repeat carrier group, and the non-carrier group. The three groups also showed no significant differences in the first year responsiveness to GH treatment. CONCLUSION: There were no significant different correlations between 19 CA repeat polymorphism and serum IGF-I levels according to genotype. Our results suggest that the IGF-I 19 CA repeat gene polymorphism is not functional in children with idiopathic short stature.

Analysis of cytosine adenine(CA) repeat polymorphism of the IGF-I gene and influence on serum IGF-I levels in healthy children and adolescents / 소아과

PURPOSE: The aim of the present study was to investigate the role of polymorphic cytosine adenine (CA) repeat of the IGF-I gene in the age-related alterations of serum IGF-I levels in healthy children. METHODS: Two hundred and forty three normal healthy children (136 boys; 107 girls) aged between 7 and 15 years were enrolled in the present study. The primers were designed to cover the promoter regions containing the polymorphic CA repeat. Data were analyzed using GeneMapper software, version 3.7. All analyses were performed using MEDCALC software packages. RESULTS: Deletion of 2 bp (G, A) following 3' of CA repeat were observed in all Korean children. The CA repeat sequences ranged from 17 to 23, and 19 CA repeat were the most common with an alleles frequency of 39.3 percent. Considering genotypes, 63.8 percent of subjects were homozygote or heterozygote for 19 CA repeat (192 bp allele), suggesting that this is wild type allele from which all other alleles originated in Korean children. Homozygote for 19 CA repeat were 14.7 percent, heterozygote for 19 CA repeat was 49.1 percent and 19 CA noncarriers totalled 36.2 percent. In 19 CA repeat noncarriers, the mean height, weight and serum IGF-I level were lower compared with those of 19 CA homozygous carriers, but statistically not significant. Correlations between serum IGF-I level and age according to the IGF-I genotypes revealed statistically significant relationships in the all groups, in the 19 CA repeat carrier group and, even in the noncarrier group. CONCLUSIONS:There were no significant differences of the mean height, weight and serum IGF-I levels among three different genotype groups. Also, there were no significantly different correlations between 19 CA repeat polymorphisms and serum IGF-I levels, according to genotype. Our results suggest that the IGF-I 19 CA repeat gene polymorphism is not associated with circulating IGF-I levels in healthy children.