Chromosomal Aberrations: Structural and Numerical Variations

Introduction

Chromosomal aberrations refer to alterations in chromosome structure or number, leading to genetic disorders. These abnormalities may be inherited or caused by environmental factors.

Types of Chromosomal Aberrations

Structural Aberrations

• Deletions: Loss of a chromosome segment, potentially leading to genetic disorders.
• Duplications: Repetitions of a chromosome segment, increasing gene dosage.
• Inversions: Reversal of chromosome segments, possibly affecting gene expression.
• Translocations: Exchange of chromosome segments between non-homologous chromosomes.

Numerical Aberrations

• Aneuploidy: Presence of an abnormal number of chromosomes (e.g., trisomy 21 in Down syndrome).
• Polyploidy: More than two complete sets of chromosomes, generally lethal in humans.

Causes of Numerical Aberrations

Chromosomal numerical variations arise from genetic predispositions and environmental influences, including:

• Errors during cell division (nondisjunction)
• Exposure to radiation or harmful chemicals
• Advanced maternal age

Conclusion

Understanding chromosomal aberrations is crucial for diagnosing and managing genetic disorders. Ongoing research continues to enhance treatments and genetic counseling.