Extra Euchromatic Band in the qh Region of Chromosome 9

Chromosomal analysis of amniotic cell culture revealed an extra euchromatic band in the variable heterochromatin region 9q12. Cytogenetic analysis of the fetus was compared with the chromosomes of the parents. Using different cytogenetic banding techniques and fluorescence in situ hybridization with specific DNA probes, the structural rearrangements involved were considered. The very rare variant proved to be familial. Demonstrating the inheritance of a normal individual supports the interpretation of the prenatal analysis of chromosome 9 as a variant without clinical relevance for the fetus.