The research article in the magazine says that brain-derived neurotrophic factor (BDNF) was pointed to be important in energy homeostasis in animal because it helps regulate appetite and weight, but little was known about its role in energy balance in humans.
Previous research had shown that heterozygous, variably sized, contiguous gene deletions cause the Wilms'' tumor, aniridia, genitourinary anomalies, and mental retardation (WAGR) syndrome.
Hyperphagia and obesity were observed in a subgroup of patients with the WAGR syndrome.
The present study started with the hypothesis that the subphenotype of obesity in the WAGR syndrome was attributable to deletions that induce haploinsufficiency of BDNF.
During the study, the researchers studied the relationship between genotype and body-mass index (BMI) in 33 patients with the WAGR syndrome.
BDNF haploinsufficiency among the patients was linked with lower levels of serum BDNF, and with childhood-onset obesity.
While a normal person has two copies of the gene that controls BDNF, the researchers found that most of the WAGR syndrome patients were missing one copy of the gene, and thus had low blood levels of BDNF.
Each of such patients was obese by age 10, and had a strong tendency to overeat.
The other people who had two working copies of the gene were no more likely than the general population to be obese or overeat, reports www.chinaview.cn.
Based on their observations, the researchers acme to the conclusion that BDNF was important for energy homeostasis in humans, and that it could help advance the understanding of obesity.