Background: Although leptin/melanocortin pathway pathologies in hypothalamus are thought to be the main cause of early-onset obesity and hyperphagia in PWS and BBS, the exact mechanism is still not known.
Objective: To measure serum concentrations of a-MSH, BDNF and AGRP in a group of children with BBS or PWS.
Methods: We recruited 12 subjects with PWS, 12 subjects with BBS, 28 obese controls (OC) and 26 lean controls (LC) matched for age, sex and puberty. Serum a-MSH, BDNF and AGRP levels were measured by the ELISA method.
Results: The mean a-MSH level was lower in PWS than those of OC and LC (3729 ± 1319, 5211 ± 829 and 5681 ± 565 pg/ml, respectively, p < 0.001), and mean a-MSH was lower in OC than LC (p < 0.05). The mean BDNF level of PWS was higher than those of OC and LC (565 ± 122, 482 ± 102 and 391 ± 74 pg/ml, respectively, p < 0.001). On the other hand, mean a-MSH level of BBS was lower than those of OC and LC (4543 ± 658, 5211 ± 829 and 5681 ± 565 pg/ml, respectively, p < 0.001), and mean a-MSH was lower in OC than LC (p < 0.05). The mean BDNF level of BBS was higher than those of OC and LC (583 ± 115, 482 ± 102 and 391 ± 74 pg/ml, respectively, p < 0.001). Additionally, both in PWS and BBS, the mean BDNF level was higher in OC than LC (p < 0.01). Regarding AGRP level, there was no difference both in BBS and PWS compared to OC.
Conclusion: We found that the serum a-MSH levels of PWS and BBS groups are significantly lower compared to those of obese and lean controls. Therefore, we can speculate that the circulating a-MSH level does properly reflect its central production, and the serum a-MSH level might be a good biomarker to detect a-MSH deficiency in individuals suspected to have BBS or PWS, and also in those with POMC, PCSK1, and LEPR deficiency.
Keywords: AGRP; BBS; BDNF; PWS; a-MSH.
© 2021. Italian Society of Endocrinology (SIE).