This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
Rett's disease is caused by abnormality in __________ 
Select and explain. 
A. ATRY, B. HLADRB1, C. MECP2, D. PTEN
C: MECP2
Answer: C: MECP2 
Explanation: 3 'M's of Rett's disease :

Mahila (F>M).
Microcephaly.
MECP2.