Duplication of the long arm of chromosome 13 secondary to a recombination in a maternal intrachromosomal insertion (shift).

A rare chromosomal aberration consisting of a chromosomal shift was found in a woman who had prenatal diagnosis because she had previously had a malformed girl with phenotypic features compatible with the diagnosis of Patau syndrome. Chromosome analysis using G, C, and NOR banding showed a direct intrachromosomal insertion of bands 13q12 to 13q14 onto the short arm of chromosome 13 at band 13p13. We discuss this observation and compare it with other published reports of chromosomal shifts.