CONSTELLATION OF CONGENITAL-ABNORMALITIES IN AN INFANT - A NEW SYNDROME OR TISSUE-SPECIFIC MOSAICISM FOR TRISOMY-18

A newborn infant born to consanguineous (first cousin) parents was not ed to have complex congenital heart defect and minor anomalies suggest ive of trisomy 18. Blood lymphocyte and skin fibroblast karyotypes wer e normal. He died in the neonatal period of postoperative complication s. On interphase fluorescence in-situ hybridization (FISH) using autop sy specimens, a significant number of cells in the liver (17%) were tr isomic for chromosome 18, compared to normal control liver tissue. How ever, interphase FISH analyses of blood lymphocytes, skin fibroblasts, and kidney tissue were normal. It is our opinion that this apparent m osaicism for trisomy 18 in the patient's liver may be spurious, though it brings into focus the issue of possible tissue/organ-specific mosa icism, The anomalies in this infant do not resemble a previously descr ibed malformation syndrome, Parental consanguinity raises the possibil ity that this represents a new autosomal recessive malformation syndro me. (C) 1996 Wiley-Liss, Inc.