RED CELL GLUCOSE-6-PHOSPHATE DEHYDROGENASE DEFICIENCY--A NEWLY RECOGNIZED CAUSE OF NEONATAL JAUNDICE AND KERNICTERUS IN CANADA

Seven male newborns of Chinese, Greek and Italian origin presented with severe hemolytic jaundice due to red cell glucose-6-phosphate dehydrogenase (G-6-PD) deficiency. In five, the hemolysis was precipitated by inhalation of mothball vapours in the home. Kernicterus was evident upon admission in six infants and was fatal in four of these.G-6-PD deficiency should be suspected as a cause of jaundice in all full-term male infants of these ethnic groups. The diagnosis can be confirmed in any hospital by the methemoglobin reduction test. In areas similar to Toronto, Canada, where these high-risk ethnic groups prevail, the following measures are recommended: (1) detection of G-6-PD deficient newborns by screening cord bloods of all infants of these ethnic groups; (2) protection of affected infants from potentially hemolytic agents such as naphthalene, certain vitamin K preparations, and sulfonamides; and (3) observation of serum bilirubin levels to assess the need for exchange transfusion for hyperbilirubinemia.

GENETIC REGULATORY MECHANISMS AT THE POPULATION LEVEL IN MAN

The distribution of the Rhesus and ABO blood groups, thalassemia, and glucose-6-phosphate dehydrogenase deficiency in Europe and in Jewish populations argues for a regulatory mechanism at the population level which adjusts gene frequencies so that the overall genetic load is not excessive, since gene frequencies giving a high genetic load at one locus are often associated with those giving low genetic loads at other loci.