Deletion 9p, duplication 18q in two sisters resulting from a maternal (9;18) (p22;q21.3) translocation.

We have studied two sisters with partial deletion 9p and partial duplication 18q resulting from adjacent 1 segregation of a maternal translocation (9;18) (p22;q21.3). The clinical manifestations identified in our patients were compared with those reported in the literature for 9p- and 18q+ patients involving approximately the same amount of genetic material. There was relatively greater similarity with the 9p- syndrome than with dup (18q) syndrome, but typical characteristics of both conditions were lacking.