The epidermal growth factor (EGF) and the dopaminergic systems in the brain are closely related to schizophrenia with respect to both etiology and treatment.
To study the mechanism of L1 transposition, we examined perinatal environmental risk factors for schizophrenia in animal models and observed an increased L1 copy number after immune activation by poly-I:C or epidermal growth factor.
These substrates are either parts of important signalling cascades (EGF, betacellulin, TGF-beta) or chemical components of myelin (neurofascin-ankyrin) known to be compromised in schizophrenia.
However, the EGF G/G genotype, which has been suggested to involve abundant production of EGF, was associated with early onset of schizophrenia in male patients.
In conclusion, although we were unable to support an association between EGFA61G and schizophrenia, the AA genotype might play a disease-modifying role differentially according to gender.
However, patients with EGF AA and TNFalpha AG/AA genotype had a lower age at onset of schizophrenia compared with the rest of the patients not having this combination (20.0 years, 3.3 vs. 30.2 years, 10.1 mean + SD; p < 0.001).