De novo case of a partial trisomy 4p and a partial monosomy 8p.

The extent of clinical expression in cases of segmental aneuploidy often varies depending on the size of the chromosomal region involved. Here we present clinical and cytogenetic findings in a 5-month old boy with a duplication of a chromosomal segment 4p16.1-->4pter and a deletion of a chromosomal segment 8p23.