RT Journal
A1 Szatmari P
T1 IS autism, at least in part, a disorder of fetal programming?
JF Archives of General Psychiatry
JO Archives of General Psychiatry
YR 2011
FD November 1
VO 68
IS 11
SP 1091
OP 1092
DO 10.1001/archgenpsychiatry.2011.99
UL http://dx.doi.org/10.1001/archgenpsychiatry.2011.99
AB 
The year 1977 marked an important milestone in the history of autism. In this year, the first twin study in autism was published by Folstein and Rutter1; it demonstrated a striking difference in concordance rates between monozygous (MZ) and dyzgyous (DZ) twins. The studies that followed reported even higher MZ concordance rates, up to 90%, for a broader phenotype resembling what is currently labeled as autism spectrum disorder (ASD)2- 4 and DZ concordance rates at or close to 0%. This resulted in heritability estimates greater than 90%, suggesting that almost all of the variance in phenotypic expression could be attributed to inherited genetic factors.