Chromosomal abberation.pptx

Introduction
Types of chromosomal aberrations
Common chromosomal disorders
Causes and diagnosis of chromosomal aberrations
Conclusion
References

1. NOIDA INSTITUTE OF ENGINEERING AND TECHNOLOGY (PHARMACY INSTITUTE) Chromosomal Aberrations Presented by: Vijyant S ingh M.Pharm 2 nd semester Submitted to: Dr. Saumya Das Associate Professor NIET(Pharmacy Institute)

2. TABLE OF CONTENT Introduction Types of chromosomal aberrations Common chromosomal disorders Causes and diagnosis of chromosomal aberrations Conclusion References

3. Introduction Chromosomal aberrations, or abnormalities, are changes to the structure or number of chromosomes, which are strands of condensed genetic material. Humans typically have 23 pairs of chromosomes, of which 22 pairs are autosomal, numbered 1 through 22. The last pair of chromosomes are sex chromosomes, which determine an individual’s sex assignment. At birth, most people with XY sex chromosomes are assigned male, and most individuals with XX are assigned female. In general, each parent contributes one set of chromosomes to their offspring, which collectively make up the 23 pairs of chromosomes. A change to any of the chromosomes, in number or structure, creates a chromosomal aberration and may cause medical disorders.

4. Types of chromosomal aberrations Chromosomal aberrations Numerical aberration Structural aberration Monosomies Trisomies Deletion Duplication Inversion Translocation

5. Common chromosomal disorders  Down syndrome Edwards syndrome   Patau syndrome  Klinefelter syndrome Turner syndrome

6. Causes of chromosomal aberrations Chromosomal aberrations are most often caused by errors during cell division. Cell division in humans occurs via mitosis or, only in sex chromosomes, meiosis. In mitosis, cells duplicate their chromosomes and produce daughter cells with an identical number of chromosomes as the original cell. In other words, a cell with 46 chromosomes will produce two cells, each with 46 identical chromosomes. Meanwhile , cell division by meiosis involves two rounds of cell division that allow for the recombination of genetic material, resulting in four sex cells with only half of the number of chromosomes. Causes of chromosomal aberrations

7. Diagnosis of chromosomal aberrations Chromosomal aberrations in offspring can often be diagnosed during prenatal screenings prior to birth. An ultrasound near the end of the first trimester or early in the second trimester can show increased nuchal translucency, which is a measure of the fluid-filled space in the back of the neck, potentially indicating trisomy 13, 18, or 21 . A blood screening may also be conducted in the late first trimester to test for pregnancy-associated plasma protein A (PAPP-A) and human chorionic gonadotropin (hCG), which may indicate a chromosomal disorder if the levels are out of their expected ranges. During the second trimester, a blood sample may be taken from a pregnant woman to conduct a “quad screen,” measuring levels of inhibin A, alpha-fetoprotein (AFP), hCG, and unconjugated estriol (uE3). A combination of high or low results can indicate different types of chromosomal disorders.

8. Diagnosis of chromosomal aberrations For diagnosis after birth, a clinician may consider the infant’s signs and symptoms and may use blood samples to run diagnostic tests, such as karyotyping and fluorescence in situ hybridization (FISH). Through karyotyping, all of the chromosomes are displayed visually in order to reveal any large structural abnormalities or numerical differences. Similarly, FISH uses fluorescent probes to visualize the genetic material, which can show both structural and numerical abnormalities.

9. Conclusion

10. References : https://www.osmosis.org/answers/chromosomal-aberrations#:~:text=Chromosomal%20aberrations%20are%20changes%20in,for%20a%20total%20of%201. Author: Corinne Tarantino, MPH Editors:  Ahaana Singh, Ian Mannarino, MD, MBA Illustrator: Abbey Richard Copyeditor: Joy Mapes