An infant with a mosaic 45,X/46,X,psu dic(Y) (pter-->q11.2::q11.2-->pter) karyotype and mixed gonadal dysgenesis studied for extent of mosaicism in the gonads.

AN infant with mixed gonadal dysgenesis was found to have a 45,X/46,Xpsu dic(Y) karyotype. A low level (8%) of mosaicism for the dic(Y) cell line was observed in peripheral blood lymphocytes and skin fibroblasts. The dicentric nature of the Y chromosome became apparent in fluorescence in situ hybridization studies. The presence of Y centromeric sequences was demonstrated in the paraffin-embedded testis and streak ovary sections. The ration of Y-positive cells was higher in the testis than in the streak ovary.

Relation of large birthweight to maternal diabetes mellitus.

The records of 517 pregnancies which terminated in the delivery of infants weighing 9 lb or more were reviewed. The obstetric patient most likely to deliver a large birthweight infant was characterized. Toxemia, prolonged labor, and puerperal morbidity occurred with increased frequency. Many of the deliveries were complicated by fetopelvic disproportion with resultant increase in mid-forceps deliveries, cesarean sections, and perinatal morbidity. Five of the 517 patients delivering large birthweight infants were known to have diabetes mellitus prior to the pregnancy included in this study. An additional 369 patients were evaluated with intravenous glucose tolerance tests. Thirty-eight (10.3%) of the 369 tested proved to have diabetic glucose tolerance curves. The likelihood of finding maternal diabetes mellitus increased with the infant's birthweight. Multiple regression analysis of other clinical variables failed to predict which patients would prove to have diabetes. Identification of diabetic puerperas requires that glucose tolerance tests be performed in all who delivered large birthweight infants.