Prenatal diagnosis of mosaic tetrasomy 5p

We report the prenatal diagnosis of a fetus with tetrasomy 5p mosaicism res ulting from a supernumerary isochromosome for the short arm of chromosome 5 . The pregnancy was terminated and fetal autopsy revealed minor facial abno rmalities (long philtrum, up-slanting palpebral fissures and a broad nasal bridge). Cultures were established from fetal skin, kidney, and pancreas fo r cytogenetic analysis; the i(5p) was observed only in the skin fibroblasts . To our knowledge, this is the fourth report of mosaic tetrasomy 5p and th e first report of prenatal diagnosis of this abnormality. Copyright (C) 200 1 John Wiley & Sons, Ltd.