Insertional translocations: report of two new families and review of the literature.

We describe two families with insertional translocations. In the first, a large family ascertained because of repeated pregnancy loss, the insertional translocation, ins(1;3)(q32;p13pter), was found to be segregating through three generations. In the second family, ascertained through a proposita with congenital malformations, multiple spontaneous abortions also occurred. The father had an insertional translocation, inv 4(p14,q21.1)ins(7,4)(q32;q21.1 q23). These cases illustrate that recurrent fetal wastage may be caused by insertional translocations and in fact may be the only clinical manifestation of this unusual type of chromosome rearrangement.