In patients with the onset of AD under 5 years of age, there is a significantly higher occurrence of sensitization mainly to lipocalins (Can f 1, Can f 2, Can f 4, Cav p 1, Fel d 4, Fel d 7), uteroglobin Fel d 1 and to Asp f 6. The gene discussed is SCGB1A1; the disease is Alzheimer disease.