Figure 3

FISH analysis of the families. Metaphase chromosome spread (A) and interphase nucleus (B) from the propositus in figure 1A, as hybridized with a PLP cosmid probe (yellow) and an X chromosome centromeric probe (red). The signal on chromosome Xq22 shows the normal PLP gene, and the signal on Xp22.1 shows the PLP duplication. The two clearly resolvable yellow signals in the interphase nucleus show the PLP duplication on either side of the red centromeric signal. C, Metaphase chromosome spread from the propositus in family 2. Hybridization was with the YAC 122e11 probe. D, Single PLP signal from control metaphase spread.