THYMUS APLASIA IN DISTAL TRISOMY 14Q SYNDROME - AN AUTOPSY CASE WITH A REVIEW OF THE LITERATURE

The present authors report an autopsy case of a malformed male newborn with de novo duplication of the distal part of the long arm of chromo some 14(14q24.1 to 14qter) in this paper. The partial trisomy of 14q w as due to the unbalanced translocation at the end of the satellite sta lk of chromosome 14. This autopsy case also had many kinds of external malformations including odd skull and facies, narrow thorax, and prom inent calcaneus as well as retentio testis. The autopsy examination re vealed aplasia of the thymus and marked hypoplasia of systemic lymphoi d tissues. During an immunohistochemical study of the lymphoid tissues the population of T cells showed only a minority of lymphocytes. Whil e several cases of distal trisomy 14q with cardiac malformations or a developmental abnormality of the thymus and the parathyroids seen in t he third and fourth pouch defects have been reported previously, the p resent case was the first of this syndrome with aplasia of the thymus and systemic lymphoid hypoplasia.