CYTOGENETIC AND MOLECULAR ANALYSIS IN TRISOMY 12P

We studied a male patient with de novo pure trisomy 12p syndrome by mo lecular analysis and fluorescence in situ hybridization (FISH) with ma rkers from chromosome 12. G-banding studies demonstrated a 46,XY, 22p karyotype and the banding pattern and clinical findings suggested tha t the extra chromosomal material was derived from 12p, Trisomy 12p was confirmed by dosage analysis with chromosome 12p markers and FISH ana lysis with a whole chromosome 12 paint, The de novo re-arranged chromo some was of paternal origin, A comparison of the clinical and cytogene tic findings in this patient was made with previously described cases of trisomy 12p, We propose a classification system for 12p trisomy in order to better characterize the correlative relationships between spe cific cytogenetic constitution and phenotype. (C) 1996 Wiley-Liss, Inc .