A PATERNALLY DERIVED INVERTED DUPLICATION OF 7Q WITH EVIDENCE OF A TELOMERIC DELETION

We report on a de novo constitutional rearrangement involving the long arm of chromosome 7 in a second trimester fetus with the karyotype of 46,XX, inv dup del (7)(pter-q36::q36-q21.2:) pat. Both a large duplic ation (q21.2-q36) and a small deletion (within q36) were confirmed by FISH studies, DNA analysis on the family showed that the abnormal chro mosome was derived from a single paternal homolog, A mechanism is prop osed in light of this finding. The phenotype at autopsy was consistent with reported cases of similar duplications in chromosome 7 in that h ydrocephalus, a depressed nasal bridge, low set ears, microretrognathi a and a short neck were present. (C) 1997 Wiley-Liss, Inc.