Mild Phenotype in a Patient With Mosaic del(8p)/inv dup del(8p)

We report on a female with a mild phenotype who is mosaic for two cell lines with different structural abnormalities of 8p, both resulting in large genomic imbalances. Molecular cytogenetic and G-banded chromosome analyses demonstrated that one cell line has a large terminal 8p deletion, with a breakpoint in 8p21.2. The other cell line contains a derivative chromosome 8, known as an inv dup del(8p) in the literature. This female has developmental delay, but lacks congenital anomalies that are associated with either 8p abnormality in non-mosaic form. The attenuated phenotype in this individual may be due to compensation of one cell line for imbalances in the other cell line. (C) 2010 Wiley-Liss, Inc.