title: Non tumoral hyperserotoninaemia responsive to octreotide due to dual polymorphism in UGT1A1 and UGT1A6.
abstract: Gilbert's syndrome is a common inherited metabolic disorder, caused by genetic aberration in the enzyme UDP-glucuronosyl-transferase 1A1 that leads to reduced glucuronidation of bilirubin. Recent advances in molecular genetics have frequently reported the concurrence of dual genetic polymorphisms in UDP glucuronosyl-transferases 1A6 and 1A1 in patients with Gilbert's syndrome, leading to defective glucuronidation of bilirubin, as well as several other endogenous and exogenous substrates, such as serotonin. We present a case of Gilbert's syndrome with severe persistent hyperserotoninaemia, mimicking carcinoid syndrome, due to dual polymorphisms in UDP-glucuronosyl-transferases 1A1 and 1A6. The patient was treated with a long-acting somatostatin analogue (octreotide) for 8 months, resulting in a significant reduction in serum serotonin levels and immediate relief of the symptomatology, followed by a long-term remission. The frequent occurrence of hyperserotoninaemia in Gilbert's syndrome may contribute, at least partly, to the nonspecific symptomatology commonly seen in these patients and should be promptly evaluated.
authors.affiliation: Division of Endocrinology and Metabolism, 1st Internal Medicine Department, AHEPA University Hospital, Aristotle University of Thessaloniki, Greece. ann.malad@hotmail.com
authors.forename: Anna
authors.initials: A
authors.lastname: Maladaki
authors.forename: Maria P
authors.initials: MP
authors.lastname: Yavropoulou
authors.forename: Kalliopi
authors.initials: K
authors.lastname: Kotsa
authors.forename: Theoni
authors.initials: T
authors.lastname: Tranga
authors.forename: Stelios
authors.initials: S
authors.lastname: Ventis
authors.forename: John G
authors.initials: JG
authors.lastname: Yovos
mesh_terms: D000328:Adult; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D004334:Drug Administration Schedule; D005260:Female; D020022:Genetic Predisposition to Disease; D005878:Gilbert Disease / Q000097:blood* / Q000235:genetics; D014453:Glucuronosyltransferase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D015282:Octreotide / Q000627:therapeutic use*; D011110:Polymorphism, Genetic; D012701:Serotonin / Q000097:blood*; D000099148:UGT1A1 Enzyme
chemical_list: D018931:Antineoplastic Agents, Hormonal; D014453:Glucuronosyltransferase; D015282:Octreotide; D012701:Serotonin; D000099148:UGT1A1 Enzyme; C110655:UDP-glucuronosyltransferase, UGT1A6