Cell proliferation rate and nuclear morphometry in Roberts syndrome

Roberts syndrome (RS) is a rare autosomal recessive disorder characterized primarily by symmetric reduction anomalies of all limbs, growth retardation and craniofacial abnormalities. Most RS patients are reported to present a typical abnormality of their constitutive heterochromatin, accompanied by abnormal cytological growth characteristics. We present an extremely severe case of an RS fetus, karyotypically documented, with a clinical presentati on including growth deficiency, tetraphocomelia, frontal meningocele, crani ofacial abnormalities and penile enlargement with hypospadias. Nuclear morp hometrical analysis in tissues of various organs revealed a reduced nuclear size in RS as compared to normal controls, and statistically significant d ifferences in morphometric parameters related to the nuclear shape. Immunoh istochemical study of the same organs showed a reduced expression of prolif erating cell nuclear antigen in the presented case, thus indicating a decre ased cell proliferation rate in RS. Our results reconfirm previously report ed findings in cultured fibroblasts of RS cases, thereby reinforcing on a h istologic level, the hypothesis that reduced cell proliferation may be invo lved in the growth retardation and the reduction abnormalities observed in RS.