Biometrics, in the medical field, helps to provide a response to the ever increasing need to automate the procedures for early diagnosis of diseases. The proposed method is undertaken by a collaboration between Politecnico di Bari and the Hospital "Casa Sollievo della Sofferenza" by S. Giovanni Rotondo, aimed at the characterization of RD (Rare Diseases). Among these, the need has arisen to compare the faces belonging to particular subjects suffering from syndromes such as, for example, Williams syndrome, characterized by the presence of morphological alterations of the face. This method can be used on stored images and is an innovative approach based on biometric comparison with respect to normalized face templates.