A clinician's view of the mass screening of the newborn for inherited diseases: current practice and future considerations.

The case for or against mass screening for inherited diseases is discussed. There is universal acceptance for mass screening for phenylketonuria and congenital hypothyroidism. The case for mass screening for galactosaemia and for maple syrup urine disease is not very strong; they could be considered under the heading of 'urgent screening of the sick newborn'. It is difficult to find good arguments for mass screening for congenital adrenal hyperplasia. For screening for glucose-6-phosphate dehydrogenase deficiency and sickle cell disease, the established criteria for mass screening do not apply. A simple tool for early detection is now available and the population afflicted with a mutant gene which causes major health problems should receive special attention from its government. It is too early to offer any comment about cystic fibrosis screening; further developments must be awaited.