title: Partial evidence of an association between epidermal growth factor A61G polymorphism and age at onset in male schizophrenia.
abstract: Epidermal growth factor (EGF) is a well-known neurotrophic factor regulating the development of various neuronal cells, including dopaminergic neurons, and dysfunction of EGF signals has been demonstrated as a risk factor for schizophrenia. Recently, several researchers have investigated associations including age at onset (AAO) with EGF A61G functional polymorphism, but the results of these studies have been controversial. Thus, we investigated whether A61G plays a role in predisposition to schizophrenia and its effects on AAO. Our subjects included 190 patients with schizophrenia and 347 controls. We assessed three different points of AAO: age at first occurrence of positive psychotic symptoms, medication, and hospitalization as a patient with schizophrenia. We found no differences in allele and genotype frequencies between patients and controls or associations between A61G and AAOs across stratified points in the entire sample and in each gender. However, we found significant gender differences in patients with the AA genotype in all stratified points of AAOs. Subset analyses of G allele distribution between clinical subsets with an AAO cutoff of 20 years revealed that male patients with early onset schizophrenia were more likely to exhibit the common AA homozygote than male patients with adulthood onset schizophrenia. In conclusion, although we were unable to support an association between EGF A61G and schizophrenia, the AA genotype might play a disease-modifying role differentially according to gender.
authors.affiliation: Clinical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Kyu Young
authors.initials: KY
authors.lastname: Lee
authors.forename: Yong Min
authors.initials: YM
authors.lastname: Ahn
authors.forename: Eun-Jeong
authors.initials: EJ
authors.lastname: Joo
authors.forename: Yeon Ho
authors.initials: YH
authors.lastname: Joo
authors.forename: Jae Seung
authors.initials: JS
authors.lastname: Chang
authors.forename: Han Young
authors.initials: HY
authors.lastname: Yoo
authors.forename: Yong Sik
authors.initials: YS
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000483:Alleles; D004815:Epidermal Growth Factor / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic / Q000235:genetics; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000235:genetics*; D012565:Schizophrenic Psychology; D012727:Sex Characteristics
chemical_list: D004815:Epidermal Growth Factor