Queston #6754Note

MECP2 gene involved in Rett syndrome is located on chromosome X (why only females are affected)
– mutation is felt to be de novo in 95% of cases (specifically on the X-carrying sperm zygote), which is why it is not typically inherited from female carriers in the traditional ways as other classic X-linked disorders 


Mutation of ELN gene on chromosome 7 = Williams Syndrome