Question

Write the numerical and structural chromosomal abnormalities represented by the following genotypes?

1) 47,XY,+18: Trisomy 18
2) 46,xy,DEL(16)p(14): Deletion of the short arm of chromosome 16
3) iso(Xq): Isodicentric chromosome X
4) 46,XX del(22)q(11.2): Deletion of the long arm of chromosome 22 at position 11.2
5) 45,X: Turner syndrome

Answer 1

The genotypes mentioned represent different types of chromosomal abnormalities such as Trisomy 18, deletion of the short arm of chromosome 16, an isodicentric chromosome X, deletion on the long arm of chromosome 22, and Turner syndrome, each with unique characteristics identifiable through a karyogram.

Step-by-step explanation:

The genotypes provided by the student represent various numerical and structural chromosomal abnormalities that are identifiable through a karyogram, highlighting the number, size, shape, and banding pattern of chromosomes. Below is an explanation of each genotype:

• 47,XY,+18: This represents Trisomy 18, where there is an extra chromosome 18, leading to 47 chromosomes in total.
• 46,XY,DEL(16)p(14): Indicates a deletion of the short arm of chromosome 16 at the band labeled 14.
• iso(Xq): Describes an isodicentric chromosome X, where there may be two identical arms of the long arm of the X chromosome.
• 46,XX del(22)q(11.2): Represents a deletion of the long arm of chromosome 22 at position 11.2.
• 45,X: Signifies Turner syndrome, characterized by the presence of only one X chromosome in an individual who is phenotypically female.

These abnormalities can have various phenotypic effects, from developmental delays to physical impairments, depending on the specific chromosome involved and the type of anomaly.