title: β2-Adrenergic receptor gene polymorphisms in the relapse of myasthenia gravis with thymus abnormality.
abstract: BACKGROUND
  The role of β2-adrenergic receptor (β2-AR) in the relapse of myasthenia gravis (MG) associated with thymus abnormality has not been fully identified.
  
  
  METHODS
  Using polymerase chain reaction and gene sequencing method, we investigated the relationship of β2-AR gene polymorphisms with different thymus pathology in MG patients. The role of β2-AR gene polymorphisms in the relapse of MG was further investigated.
  
  
  RESULTS
  Age of onset (p = 0.034), the onset symptom of ocular MG (OMG; p = 0.023), the first symptom of OMG second generalization (p = 0.040) were different in MG with thymoma from those in MG with normal thymus or thymus hyperplasia. Gene polymorphisms of β2-AR on positions 16 and 27 showed no significant difference between relapsed and non-relapsed MG patients with thymus abnormality (thymus hyperplasia: position 16, p = 0.792; position 27, p = 0.664; thymoma: position 16, p = 0.226; position 27, p = 0.615). However, genotypes distribution on position 27 among MG patients with three thymus histology was significantly different (χ² = 8.153, p = 0.041). Furthermore, glucocorticoid can decrease relapse of MG with thymus hyperplasia (p = 0.021).
  
  
  CONCLUSIONS
  MG patients with thymus abnormality differ from MG patients with normal thymus in age of onset, the onset symptom of OMG and the first symptom of OMG second generalization. β2-AR gene polymorphisms had no relationship with the relapse of MG with thymus abnormality. Gene polymorphism of β2-AR on position 27 was associated with different thymus histology of MG. Glucocorticoid was able to reduce the risk of relapse of MG with thymus hyperplasia.
authors.affiliation: a Department of Neurology, Beijing Shijitan Hospital , Capital Medical University , Beijing , China.
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.affiliation: a Department of Neurology, Beijing Shijitan Hospital , Capital Medical University , Beijing , China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: a Department of Neurology, Beijing Shijitan Hospital , Capital Medical University , Beijing , China.
authors.forename: Maolin
authors.initials: M
authors.lastname: He
mesh_terms: D000328:Adult; D017668:Age of Onset; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000235:genetics* / Q000473:pathology*; D011110:Polymorphism, Genetic / Q000235:genetics*; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics*; D018709:Statistics, Nonparametric; D013950:Thymus Gland / Q000002:abnormalities*
chemical_list: D018343:Receptors, Adrenergic, beta-2
keywords: adrenergic receptor; myasthenia gravis; prognosis; thymus