Prader Willi syndrome
Myotonic dystrophy
Kartagenar’s syndrome
Kennedy’s disease:
Spinobulbar muscular atrophy or Kennedy’s disease is an X linked condition characterized by late onset (at about the age of 30), progressive neurone degeneration, muscular weakness, and male infertility due to testicular atrophy.
The molecular mechanism is the expansion (in excess of 38-40 repeats ) of the trinucleotide repeat sequence (CAG) located in exon 1 of the androgen receptor (AR) gene located on chromosome Xq11-12, which causes an abnormal polyglutamine stretch in the receptor protein. This causes dysfunction of the androgen receptor to the action of circulating androgens.
