Nodulocystic acne and an extra Y chromosome [Acne nodulo-cistica e cromosoma Y soprannumerario]

In order to study the frequency of an extra Y chromosome in nodulocystic acne (NCA), the karyotype of 37 male patients with NCA was examined by both classic and quinacrine methods. Moreover, a statistical study was carried out to ascertain the frequency of the XYY phenotype in a large population of acne patients. The chromosomes in metaphase plates and the F-bodies in interphase cells were normal in all subjects examined. The statistical study did not reveal any significant differences between the phenotype of acne and normal subjects. These findings indicate that an XYY karyotype in NCA patients must be considered a rare event.