Transient neonatal diabetes mellitus in half sisters. A sequel.

This is a sequel to a previous report of two half sisters with transient neonatal diabetes mellitus. In 1970, the same syndrome developed in a third half sibling, a boy, born of the same father by his third wife. It followed essentially the same neonatal clinical course as that of his two half sisters. The firstborn sibling, aged 19 years, is reported to be free of signs and symptoms of diabetes; the third born was clinically well with no glycosuria at 9 years 3 months of age, and was reported to be in good health at 11 years of age. In 1978, at age 15 years diabetic ketoacidosis and coma developed in the second-born sister and she has had insulin-dependent diabetes since that time. These cases present a unique genetic pattern and, to our knowledge, there have been no reports of cases of transient neonatal diabetes becoming full-blown type I insulin-dependent diabetes mellitus later in life.