A second case of inv(4)pat with both recombinants in the offspring: rec dup(4q) in a girl with Wolf-Hirschhorn syndrome and rec dup(4p)

In a girl presenting with features of Wolf-Hirschhorn syndrome, cytogenetic and molecular cytogenetic analysis revealed a rearranged chromosome 4 with monosomy of the distal bands 4pter-->4p16.2 and trisomy of the distal band s 4q35.1-->4qter [rec dup(4q)] due to a large, paternal pericentric inversi on. In the following two pregnancies, prenatal diagnosis showed the same im balance in one fetus and a reverse segmental imbalance [rec dup(4p)] in the other. We discuss the recombination risk of the given inversion with respe ct to the size of the inverted segment and the viability of the recombinant s. The high frequency of recombinants in this family and others suggests a high recurrence risk in similar cases with large pericentric inversions com prising almost entire chromosomes. Copyright (C) 2001 S. Karger AG, Basel.