The relationship in Japanese infants between a genetic polymorphism in the promoter region of the insulin-like growth factor I gene and the plasma level.
BACKGROUND
Evidence is accumulating that the promoter region of the insulin-like growth factor I (IGF-I) gene polymorphism and low levels of IGF-I are associated with type 2 diabetes, cardiovascular disease and birth weight; however, the number of wild-type alleles is different in each country.


OBJECTIVE
This study aimed to examine the 737/738 marker, a cytosine-adenine repeat in the promoter region of the IGF-I gene polymorphism, and plasma IGF-I levels in Japanese infants and analyze the genetic background.


METHODS
Data were collected for 15 months in Kyoto Prefectural University of Medicine. The body composition parameters of all infants were determined at birth. At 5 days after birth, we took blood samples to measure the product size of the promoter region of the IGF-I gene polymorphism and plasma IGF-I.


RESULTS
In a population-based sample of 160 subjects, 6 different alleles and 16 genotypes were identified in the promoter region of the IGF-I gene polymorphism. The existence of a 196-bp allele has proved to result in a low plasma IGF-I level, a small head and chest circumference (p < 0.05) and no significant for premature birth, short-birth height and low-birth weight.


CONCLUSIONS
This is the first study showing the role of the promoter region of the IGF-I gene polymorphism and the level of plasma IGF-I and body composition parameters in Japanese infants. Our results suggest genetical influence on prenatal growth and serum IGF-I levels.
Kinoshita
Yumiko
Y
Department of Pediatrics, Kyoto Prefectural University of Medicine, Kyoto, Japan. kinoshi@koto.kpu-m.ac.jp
Kizaki
Zenro
Z
Ishihara
Yasunori
Y
Nakajima
Hisakazu
H
Adachi
Shinsuke
S
Kosaka
Kitaro
K
Kinugasa
Akihiko
A
Sugimoto
Tohru
T
D049628:Body Size; D005260:Female; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics*; D005820:Genetic Testing; D005838:Genotype; D006785:Hospitals, University; D006801:Humans; D007231:Infant, Newborn; D007334:Insulin-Like Growth Factor I / Q000032:analysis* / Q000235:genetics*; D007564:Japan / Q000453:epidemiology; D008297:Male; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics
D005819:Genetic Markers; D007334:Insulin-Like Growth Factor I