Isolated sacral agenesis in a fetus monosomic for 7q36.1-->qter.

A fetus with severe sacral agenesis and intrauterine growth retardation, ascertained at prenatal diagnosis, was found to be carrying an unbalanced form of a paternal balanced reciprocal translocation (7;19)(q36.1;q13.43), resulting in functional monosomy for 7q36.1-->qter. Necropsy confirmed that the fetus had isolated sacral agenesis type II. A critical region for autosomal dominant sacral agenesis has recently been mapped to the 7q36 region. This case provides further evidence for a sacral agenesis locus in this region and may help to refine the critical region further.