Give examples of disorders caused by sex chromosomal abnormalities and describe them briefly.

(N/A) Examples of sex chromosomal abnormalities include Klinefelter's syndrome (trisomy) and Turner's syndrome (monosomy).
$1$. Klinefelter's Syndrome $(47, XXY)$: This genetic disorder is caused by the presence of an additional copy of the $X$ chromosome,resulting in a karyotype of $47, XXY$.
- Individuals have an overall masculine development,but they are sterile.
- Testes are underdeveloped.
- They exhibit tall stature,long limbs,and sparse body hair.
- They may show feminine characteristics such as gynecomastia (development of breast tissue) and a high-pitched voice.
- Some individuals may exhibit mild mental retardation.
- It occurs in approximately $1$ in $1500$ individuals.
$2$. Turner's Syndrome $(45, XO)$: This disorder is caused by the absence of one $X$ chromosome,resulting in a karyotype of $45, XO$.
- Such individuals are sterile females.
- They have short stature and a webbed neck.
- Ovaries are rudimentary and the uterus is underdeveloped.
- Lack of secondary sexual characteristics is observed.