Hereditary sever combined immunodeficiency and adenosine deaminase deficiency

A retrospective study aiming at detection of heterozygous carriers of blood adenosine deaminase (ADA) deficiency was carried out in nine families known to us because children had died of combined immunodeficiency (SCID). The trait was found in 3 of 9 parent couples, and in 14 other relatives. In two families one homozygous patient was identified. A total of 54 family members and 60 healthy control subjects were tested. Clinically, the patients were all characterized by marked lymphopenia, nearly normal immunoglobulin levels, and inability to produce antibodies. One homozygous patient recovered after transplantation of fetal liver and thymus and is immunologically normal 1.5 years afterwards.