Journal of the Medical Association of Thailand Vol 92, No 12:DECEMBER 2009 (SUPPL.7) 0125-2208 92 12 2009 Dec Identification of Leptin Gene Variants in School Children with Early Onset Obesity 108 EN Paleerath Kongmacheep Chutima Sirikulchayanonta Rungsunn Tungtrongchitr Kitiphong Hancharoen Original Article To investigate leptin gene variations in Thai primary school children. Direct DNA sequencing was performed following polymerase chain reaction (PCR)amplification of the leptin gene in 30 obese children aged 10-12 years old. A heterozygous variant 19 (G > A), located in the non-coding region of exon 1 was detected in 13subjects (43.3%, A: 0.22). Only 2 subjects (6.7%, G: 0.03) harbored a heterozygous (CAA > CAG) polymorphismin codon 25 of exon 2. The 25 (CAA > CAG) polymorphism appeared to be a new leptin gene variant in Thai people.This study provides basic information concerning the prevalence of leptin gene polymorphisms in Thaichildren with early onset obesity. It might be useful as genetic marker for screening for obesity potential inlarge populations. Leptin Gene variation Polymorphism Obesity School children