Chromosomal Mutation Types

Chromosomal Mutation

Duplication

• A type of chromosomal mutation where a segment of a chromosome is copied and inserted elsewhere in the genome
• Can occur in tandem (adjacent to the original segment) or at a distant location
• May result in an increase in gene dosage, leading to changes in gene expression
• Can also disrupt gene function or create novel genes with new functions

Translocation

• A type of chromosomal mutation where a segment of a chromosome breaks off and attaches to a non-homologous chromosome
• Can be reciprocal (exchange of segments between two chromosomes) or non-reciprocal (attachment of a segment to a non-homologous chromosome)
• Can lead to changes in gene expression, disruption of gene function, or creation of new genes
• Can also result in infertility or increased risk of cancer

Inversion

• A type of chromosomal mutation where a segment of a chromosome breaks off, flips, and reattaches to the same chromosome
• Can be pericentric (involving the centromere) or paracentric (not involving the centromere)
• May result in changes to gene expression or disruption of gene function
• Can also lead to infertility or increased risk of miscarriage

Chromosomal Mutation

Duplication

• A chromosome segment is copied and inserted elsewhere in the genome
• Occurs in tandem (adjacent to the original segment) or at a distant location
• Increases gene dosage, altering gene expression
• Disrupts gene function or creates novel genes with new functions

Translocation

• A chromosome segment breaks off and attaches to a non-homologous chromosome
• Reciprocal: exchange of segments between two chromosomes
• Non-reciprocal: attachment of a segment to a non-homologous chromosome
• Changes gene expression, disrupts gene function, or creates new genes
• Causes infertility or increases cancer risk

Inversion

• A chromosome segment breaks off, flips, and reattaches to the same chromosome
• Pericentric: involves the centromere
• Paracentric: does not involve the centromere
• Alters gene expression or disrupts gene function
• Causes infertility or increased miscarriage risk

Chromosomal Mutation

Duplication

• A type of chromosomal mutation where a segment of a chromosome is copied, resulting in an extra copy of genetic material
• Occurs in two ways: tandem duplication (copied segment attached to the original segment) and interstitial duplication (copied segment inserted elsewhere in the same chromosome)
• Effects: increased gene expression, gene redundancy (leading to gene evolution), and increased risk of gene mutation and disease

Translocation

• A type of chromosomal mutation where a segment of a chromosome breaks off and attaches to a non-homologous chromosome or a different location on the same chromosome
• Types: reciprocal translocation (exchange of segments between two non-homologous chromosomes) and Robertsonian translocation (fusion of two acrocentric chromosomes)
• Effects: disruption of gene function and regulation, increased risk of infertility, miscarriage, and birth defects, and creation of chimeric genes and cancer development

Inversion

• A type of chromosomal mutation where a segment of a chromosome breaks off and reattaches in reverse order
• Types: paracentric inversion (occurs within a single arm of a chromosome) and pericentric inversion (occurs on both sides of the centromere)
• Effects: disruption of gene function and regulation, increased risk of chromosomal abnormalities and disease, and formation of chromosomal loops and aberrant gene expression