Clinical and molecular cytogenetic analysis of a rare case of mosaicism for partial trisomy 3p and partial trisomy 10q in humans

The results of comprehensive clinical examination and molecular cytogenetic analysis of a patient carrying chromosome 3p+ in 69% of the peripheral blo od lymphocytes are presented. Using microdissection of the metaphase chromo somes followed by DOP-PCR, a DNA library specific for the abnormal chromoso me was obtained. By fluorescence in situ hybridization (FISH) of this DNA l ibrary on chromosomes from the patient and a healthy donor, the aberrant ch romosome was identified as der(3)t(3;10)(p25;q24.3). Since this chromosome was present in only a proportion of patient's cells studied and no chromoso me aberrations were revealed in cells of his parents, the der(3)t(3;10) is suggested to appear de novo. The cells carrying der(3)t(3;10) are monosomic for a proportion of 3p25 and trisomic for 10q24.3 --> qter. The developmen tal malformations revealed in the patient, such as the specific features of facial skeleton, mental retardation, microcephaly, and others are similar to those described previously in patients with partial 3p monosomy and 10q trisomy.