Adenosine-deaminase deficiency in a child diagnosed prenatally.

Deficiency of red-blood-cell adenosine deaminase (R.B.C.-A.D.A.) has been reported in a proportion of patients with the autosomal recessive form of severe combined immunodeficiency (S.C.I.D.). In a family in which a child had died with S.C.I.D., R.B.C.-A.D.A. levels in the parents and other members of the family were compatible with a heterozygous state for A.D.A. deficiency. Cultured amniotic-fluid cells obtained from a subsequent pregnancy contained less than 1.5% of A.D.A. activity of normal amniotic cultures. The prenatal diagnosis of A.D.A. deficiency was confirmed at birth by the absence of A.D.A. ACTIVITY IN THE CHILD'S RED-BLOOD-CELLS. Clinical and laboratory findings in this child are similar to those of the sibling who had died with S.C.I.D.