Evaluating each genetic condition. Klinefelter's syndrome is correctly described as 47, XXY, involving an extra X chromosome in males.
Turner's syndrome should be 45, X, not 45, XY. This syndrome is characterized by the presence of a single X chromosome and the absence of the second sex chromosome, not an XY configuration.
Down syndrome is accurately described as having an extra 21st chromosome, leading to a total of 47 chromosomes.
Edward syndrome is also correctly identified with an extra 18th chromosome, resulting in 47 chromosomes.
If the roots of $\sqrt{\frac{1 - y}{y}} + \sqrt{\frac{y}{1 - y}} = \frac{5}{2}$ are $\alpha$ and $\beta$ ($\beta > \alpha$) and the equation $(\alpha + \beta)x^4 - 25\alpha \beta x^2 + (\gamma + \beta - \alpha) = 0$ has real roots, then a possible value of $y$ is: