chromosomal abberations

1. CHROMOSOMAL
ABBERATIONS
PRESENTED BY:
M.C.KNIRANDA
ASSISTANT PROFESSOR
SSNSR, SU.

2. INTRODUCTION
• The word ‘Chromosome’ is derived from Greek word “chroma”-color and
“soma”- body .
• Normally in males we have 44+xy and in female we have 44+xx chromosomes
• A female ova consists of 23 chromosomes and sperm consists of 23
chromosomes so after fertilization a zygote comprises of 46 chromosomes(23
pairs)

3. DEFINITION
• Chromosomal aberrations are disruptions in the
normal chromosomal content of a cell.
• In other words, they are changes in the number and
or arrangement of genes in the chromosomes.

4. ETIOLOGY
1) Meiosis-if there is an error in cell division, the egg or
sperm can end up with too many or not enough
chromosomes.
2) Mitosis- if the chromosome do not split into equal halves,
the new cells can have an extra chromosome or have a
missing chromosome.

5. 3) Maternal age- eggs are also aging and may have the incorrect
number of chromosomes at the time of fertilization.
4) Consanguinity- it describes a relationship between two people
who share a common ancestor or a shared blood relationship .
5) Radiations- it is teratogenic
6) Environment- it may include medications, foods, etc.
ETIOLOGY