[Screening for hereditary diseases. What other screening?].

Faced to the success of the neonatal screening for phenylketonuria and congenital hypothyroidism, it was tempting to introduce screening of other metabolic diseases. "Ideal" diseases to be screened are treatable, are not easily recognized by clinical means during the neonatal period, need immediate therapy to prevent irreversible disabilities, have a reasonable frequency and can be detected by and easy test. There is some controversy concerning the list of diseases recommended for mass screening, among them four can be discussed: congenital adrenal hyperplasia, due to 21-hydroxylase deficiency, fulfils most of the criteria, but some changes in the general screening strategy should be made to provide a result as soon as possible, and at least before the 10th day of life; cystic fibrosis, immunoreactive trypsin is a good marker of the disease but its assay needs technical adaptation for mass screening; more information are also required about the efficacy of an early management of the disease; Duchenne muscular dystrophy has a good marker for neonatal screening (creatine kinase), but no treatment exists and the possibility of genetic counselling can only be provided; hypercholesterolaemia is a frequent disease; however, the good marker and the adequate treatment remain to be defined. Pilot programmes, on the behalf of the French Association for Neonatal Screening, are evaluation these problems. However, at the present time, a consensus has been reached that only phenylketonuria and hypothyroidism fulfils criteria for an efficient mass screening programme.