Pathogenic factors in idiopathic mental retardation.

Pathogenic factors in a mentally retarded population were evaluated by comparing their frequency among three groups of patients: a control group with predominantly genetic retardation and consanguineous parents; a group with severe idiopathic retardation and unrelated parents; and a group with mild idiopathic retardation and unrelated parents. Seven factors were found to be significantly more common among the patients with idiopathic retardation than in the genetic control group: a history of maternal reproductive inefficiency; bleeding during pregnancy; toxemia during pregnancy; signs of perinatal stress; neonatal anoxia; neonatal jaundice; and seizures during the first year of life. A history of repeated maternal abortions was particularly associated with mild retardation, and infantile seizures were particularly associated with severe retardation.

The association of maternal and neonatal thrombocytopenia in high-risk pregnancies.

In this study of 136 women with pre-eclampsia, eclampsia, placenta previa, or abruptio placentae, 21 mothers were noted to have thrombocytopenia. Seventeen of the 21 were in the pre-eclampsia group. Of the 21 thrombocytopenic mothers, nine were associated with thrombocytopenia in the children, seven children had normal platelet counts, and five had no counts performed.

Hemoglobin Fort Gordon or alpha2beta2145 Tyr replaced by Asp, a new high-oxygen-affinity hemoglobin variant.

Hemoglobin Fort Gordon, alpha2beta2145 Tyr replaced by Asp (HC2), has been observed in a 20-year-old black male with compensatory erythrocytosis. The variant was readily identified by electrophoresis and chromatography, and comprised about 30% of the red cell hemoglobin. The substitution was identified through analyses of tryptic peptides of various digests of the isolated beta chain.