Evidence of chromosome 9 origin of the euchromatic variant band within 9qh

Fluorescence in-situ hybridization studies using a whole chromosome 9 painting probe were performed on three individuals from two different families, who carry a chromosome 9 variant with an extra band within the elongated 9qh region. The results confirm the euchromatic nature of the extra band, and provide evidence that it is of chromosome 9 origin. This variant band, which may not be very rare, thus possibly results from a duplication of a segment of 9qh plus band p12 or part of band q21.