Roberts' syndrome.I. Cytological evidence for a disturbance in chromatid pairing

Abstract

In the rare developmental disorder Roberts'' syndrome [which is characterized by short, malformed extremities, deformities of the maxilla including cleft palate and growth retardation], prophase and metaphase chromosomes display premature sister chromatid separation, most prominently at certain regions where the chromatin is composed of highly reiterated base sequences. Interphase nuclei present a striking distortion in their contours. The observed abnormalities are interpreted as evidence for the presence of a genetically determined distrubance affecting the normal mechanisms for pairing and disjoining of sister chromatids.