[Ring chromosome 13 and multiple malformations (author's transl)].

A male infant with a ring chromosome identified by R, D and G banding techniques is reported. Karyotype was 46, XY,r(13)(p12q22). The main clinical features were severe mental retardation, microcephaly, frontal bossing a peculiar Greek profile, microphtalmia, coloboma, high and narrowed palate, low-set ears and genital anomalies. The three groups in the 13q deletion syndrome proposed by Niebuhr and Ottosen (1973) are commented. These groups are based on clinical features and loss of segment in the long arms of chromosome 13. Our patient has many of the clinical features of the first group.