Question

Someone with an extra X chromosome added to the XY combination, resulting in a chromosomal make-up of a total of 47 chromosomes (sex chromosomes are XXY), describes an intersex condition known as:

Select one:

a. Klinefelter syndrome
b. Congenital adrenal hyperplasia (CAH)
c. Turner syndrome
d. Androgen insensitivity syndrome (AIS)
e. 5-alpha reductase deficiency (5ARD)

Answer 1

Klinefelter syndrome is characterized by an XXY chromosomal makeup resulting in phenotypical features like small testes and enlarged breasts, along with learning challenges in affected individuals.

Step-by-step explanation:

The condition where an individual has an extra X chromosome in addition to the usual XY chromosome pair, resulting in an XXY chromosomal makeup, is known as Klinefelter syndrome. This genotype corresponds to a phenotype where individuals typically have small testes, enlarged breasts, and reduced body hair.

In addition, such individuals may have intellectual and learning challenges. The extra X chromosome undergoes a process called inactivation, except for one, in order to manage the excess genetic dosage, which is a notable mechanism in Klinefelter syndrome and other chromosomal abnormalities like Turner syndrome, which is characterized by an XO genotype.