Clinical features in a case with ring chromosome 13.

A 30-month-old boy with severe psychomotor retardation and numerous developmental anomalies, such as small trigonocephalic head, craniofacial anomalies, malformations of fingers with hypoplastic thumbs, anomalies of urogenital organs and imperforate anus, is presented. Cytogenetic studies of peripheral blood lymphocytes with differential staining of chromosomes revealed 46,XY,r13 karyotype. The correlation between clinical features and the observed chromosome aberration is discussed. Hitherto unreported developmental brain anomalies with partial exhibited skeletal abnormalities, some not reported previously.