Mutation

Chromosomal Mutation

Changes of chromosomal number

Aneuploidy : is the presence of an abnormal number of chromosomal in a cell

Euploidy : is the presence of an abnormal entire set of chromosome in a cell

Changes of chromosomal structure

  1. Delation
  1. Inversion
  1. Duplication
  1. Translocation

1.1 Terminal : single break in any one end of the chromosome

1.2 Interstital : caused by 2 breaks & reunion of terminal parts leaving the middle

2.1 Paracentric : An inversion which takes place apart from the centromere

2.2 Paricentric : An inversion that includes the centromere

: arrangement of the same order of genes repeated more than one in the same chromosome

: occurs us result of interchange of chromosome segments in non-homologous chromosome

Gene Mutation

  1. DNA level

1.1 Base-pair substitution

1.1 Transition : Changes a purine nucleotide to another purine or pyrimidine to another pyrimidine

1.2 Transversion : Single purine changed to pyrimidine or vice versa

1.2 Insertion

: Adding of nucleotide and the reading frame shifted

1.3 Duplication

: Arrangement of the same order of nucleotides repeated more than once in the same chromosome

1.4 Deletion

: The deletion of nucleotides, then make the frameshift

  1. Protein level

2.1 Silent

: New codon encodes the same amino acid after transition mutation, no effect on the amino acid sequence

2.2 Missense

: New codon encodes a different amino acid due to transition mutation/change of a single nucleotides that results in a codon for a different amino acid

2.3 Nonsense

: New codon is a stop codon(UAA) due to transition mutation, it leads to premature termination translation. Effects depends on how close the new stop codon os to the beginning of the coding sequence

2.4 Frameshift

: The result of deletion or intersection of nucleotides less than 3. Frameshift mutation change the reading frame, 'framing error, a reading frame shift, indel mutation