THREE SIBLINGS are depicted in Figure 1. The girl, aged 9 years, is flanked by her 8-year-old fraternal twin brothers. The twin on the left of the photograph is mentally retarded and the twin on the right is not.
Tsuchiya KD, Forsythe M, Robin NH, Tunnessen WW. Picture of the Month. Arch Pediatr Adolesc Med. 1998;152(1):89-90. doi:10.1001/archpedi.152.1.89