Barr body is not present in female having- (PGMEE 2012-13)

In Turner syndrome (45, XO),one of the X-chromosome is missing in a female. This is the most lethal karyotype. It is only monosomy of sex chromosome in humans. There are 45 chromosomes instead of 46 in a normal individual. Phenotype Genotype Barr bodies Normal Male XY 0 (Normal) Normal Female XX 1 (Normal) Turner Syndrome X0 0 (Female with no Barr Body) Klinfelter Syndrome XXY 1 (Male with Barr Body) Super Female XXX 2 (Female with two Barr Bodies) No. of Barr bodies = no. of x chromosome - 1 Since in XO genotype there is 1 x chromosome. Therefore, no. of barr bodies is 1-1=0