THYMIC ALYMPHOPLASIA WITH XX/XY LYMPHOID CHIMERISM SECONDARY TO PROBABLE MATERNAL-FETAL TRANSFUSION

Karyotypes in a 5-month-old patient with thymic alymphoplasia revealed evidence for XX/XY chimerism in peripheral blood lymphocytes. These cells showed no immunologic competence, and there was no indication of a graft-versus-host reaction (GVHR). These findings suggest that placentally transfused maternal lymphocytes may persist in an immunologically incompetent fetus without having a demonstrable effect. Additional findings included adrenal hyperplasia, possible absence of parathyroids, and lack of evidence of immunologic function after attempts at grafting fetal thymic and hematopoietic tissue. © 1969 The C. V. Mosby Company.