MR has many different causes. In some instances injury, genetic/chromosomal abnormalities, or infection causes MR. These causes can occur before birth or during childhood (up to age 18).
1:48
7:01
1:57
1:05
5:21
1:45
2:16
1:54
35:56
2:54
2:00
:50
2:04
1:06
1:08
:29
5:19
:51
:27
1:12
1:37
2:44
2:28