chromosomal abberations.pptx

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

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