High plasma neurotensin levels in children with Prader-Willi syndrome.

Prader-Willi syndrome (PWS) is an obesity-related genetic condition, most commonly due to a paternal deletion of the chromosome 15q11-q13 region. PWS is characterized by growth hormone deficiency, infantile hypotonia and feeding problems, hypogenitalism/hypogonadism, increased pain threshold and thermal instability, decreased gastric motility, and hyperphagia in childhood leading to severe obesity. Neuro-endocrine peptides are known to influence gastric function and pain sensation which led us to measure a specific peptide that may be involved [i.e., neurotensin (NT)] in PWS and compared with unrelated control siblings. Overnight fasting plasma NT levels were obtained from 23 children with confirmed PWS (age: 8.2 ± 2.0 years; range: 5-11 years) and 18 unaffected, unrelated siblings (age: 8.2 ± 2.3 years; range: 5-11 years) and measured using Multiplex sandwich immunoassays with the Luminex magnetic-bead based platform. Plasma NT levels were natural log-transformed and analyzed by ANOVA with adjustments for age, gender, and body mass index (BMI). No difference was found in plasma NT levels for gender, age or BMI or significant correlations seen with age or BMI. Higher plasma NT levels (P < 0.001) were seen in PWS children (mean of 626 ± 238 pg/ml) compared with unaffected, unrelated siblings (mean of 371 ± 236 pg/ml). Plasma levels were also higher in children with maternal disomy 15 (736 ± 182 pg/ml) compared with those having the deletion subtype (548 ± 247 pg/ml, P < 0.04). Although no measures for pain threshold, thermal instability or gastric motility were performed in our study participants, higher plasma NT levels were found in PWS children.