7.Etiology of inherited disorders.Mutagenesis.Definition and classification of gene mutations.Phenotypic effect of mutations.Germline and somatic mutations (copy)

Mutagenesis

The process of inducing mutations in genetic material.

Chemical mutagens

Mutagens that include alkylating agents and base analogs.

Physical mutagens

Mutagens that include ionizing radiation and UV radiation.

Biological mutagens

Mutagens that include certain viruses.

Point mutations

Mutations that involve single base changes.

Insertions and deletions

Mutations that involve the addition or removal of bases.

Chromosomal rearrangements

Mutations that involve translocations or inversions.

Gene mutation

An alteration in the DNA sequence of a gene.

Spontaneous mutations

Mutations that occur due to molecular decay.

Tautomerism

A base is changed by the repositioning of an H atom.

Depurination

Loss of a purine base (repair mechanism exists).

Deamination

Removal of an NH2 group by hydrolysis (NO REPAIR MECHANISM).

DNA damage

Errors induced in DNA repair.

Missense mutation

A single base change leading to an amino acid substitution.

Nonsense mutation

A single base change leading to a premature stop codon.

Frameshift mutation

Insertion or deletion of bases, altering the reading frame.

Silent mutation

A single base change without changing the amino acid sequence.

Splice site mutation

Alteration in the intron-exon boundary, affecting mRNA splicing.

Point mutation

A change in a single nucleotide.

Deletion

Removal of a nucleotide.

Trinucleotide repeats

Repeated sequences of three nucleotides.

Transition

Replacement with a base from the same group (ex. A-G).

Transversions

Replacement of a base with one from the other group (ex. A-C).

Loss-of-function mutations

Mutations that result in reduced or absent protein function.

Gain-of-function mutations

Mutations that lead to abnormal protein function or increased activity.

Dominant-negative mutations

Mutations where the mutant protein interferes with the function of the normal protein.

Haploid sufficiency

One functional copy of a gene is insufficient to maintain normal function.

Amplifications/gene duplications

Multiple copies of all chromosomal regions.

Deletions of chromosomal regions

Mutations that involve the removal of chromosomal regions.

Chromosomal rearrangements

Mutations that involve translocations and inversions.

Loss of heterozygosity

Loss of one of the alleles.

Somatic mutations

Mutations that occur in a single somatic cell and cannot be inherited.

Germline mutations

Mutations that occur in gametes and can be passed on to offspring.