How can mutation cause genetic disorders?

When a mutation occurs in the sex cells (egg or sperm) of a person, these mutated genes can be passed on to their children. Sometimes these genes aren't harmful, but other times, they can be expressed as genetic disorders.

I hope that this helps.

Depends on mutation, A chromosomal mutation affects a whole chromosome (english translation, the whole chromosome made is mutated) the other ones, point and the other i forgot, affect 1 part of the cell created.

Fragile X is a classic example of how a mutation can become a genetic disorder.

Fragile X is also interesting as research has discovered that this mutation not only affects children with over 200 repeats of the CGG sequence (usually identified as a full-mutation, a individual with a "normal" gene has approximately 6-50 repeats) but also carriers (usually identified as a pre-mutation, individuals with 50 - 200 repeats). A high percentage of female carriers have Premature Ovarian Failure (POF aka early menopause), and a high percentage of older carriers develop FXTAS (mostly males over the age of 50, but can affect females as well).

I won't go into extreme detail, you can get that from the websites listed below.