Wilms’ tumors are the common embryonic childhood tumor and heterogeneous in nature. Karyotypic analysis of Wilms’ tumor has shown a variety of chromosomal aberrations with different (%) frequency of structural and numerical changes in somatic cell. Present study were carried out in eleven cases (n=11) of Wilms’ tumors with different age group (betwen 1.5 year to 10 year). Most striking feature is the involvement of high frequency (>60%) of Wilms’ tumor shows extra copy of chromosome -21 in the karyotypes after using high resolution of GTG banding and FISH analysis. Interestingly, 18% cases of Wilms’ tumor shows loss of Ychromosome and appearance of (r) Y reporting first time in India. Beside this, short arm of chromosome-6 and 16 shows two new break points i.e. 6q21.22 and 16q23 might have play an significant role in Wilms’ tumors progression. The another relevant were the association of either gain (trisomy) or loss (monosomy) of chromosome with chromatid break points, ring, dicentric or rearrangements of chromosome (translocation) with different frequency. However, this is a rare coincidence that environmental factor (s) might have increase risk of developing down syndrome (47, XY+21) in Wilms’ tumors, due non-disjunction event and unequal crossing over in cell- division of the disease outcome.
