Deletion and mutation disorders

 

·        Disorders in portions of a  chromosome are  four in number though many other forms exists A)  Deletions.B) Insertions.

C) Gene mutation:

What is meant by insertion disorders?? insertion implies  addition of a base into the gene sequence

 

·        Q.1     ; What is deletion disorder ?? :- Deletion– When a base or some bases deleted from the gene sequence. ...

·        Inversion– When some gene sequences inverted and inserted back into the original sequence. ...

·        Substitution– When some bases of a gene sequence are replaced by other bases.

Deletion is a type of mutation involving the loss of genetic material. It can be small, involving a single missing DNA base pair, or large, involving a piece of a chromosome. There are three types of genetic disorders:

·        A) Single-gene disorders, where a mutation affects one gene. Sickle cell anemia is an example.

·        B) Chromosomal disorders, where chromosomes (or parts of chromosomes) are missing or changed. ...

·        C) Complex disorders, where there are mutations in two or more genes.

 

Q.2: What about mutations?? There are three types of DNA Mutations: base substitutions, deletions and insertions.

·        . Single base substitutions are called point mutations, recall the point mutation Glu -----> Val which causes sickle-cell disease.

There are four classes of mutations , Such are (1) spontaneous mutations (molecular decay), (2) mutations due to error-prone replication bypass of naturally occurring DNA damage (also called error-prone translesion synthesis), (3) errors introduced during DNA repair, and (4) induced mutations caused by mutagens.