Table 1. Characteristics of the twin study sample.
ASD discordant twin pairs (N=20 individuals)* | ASD concordant twin pairs (N=12 individuals) | Non-ASD twin pairs (N=44 individuals)† | ||
---|---|---|---|---|
Gestational week | 34.7±4.6 | 34.7±1.5 | 36.0±3.5 | |
Age at assessment | 14.7±3.9 | 11.5±3.0 | 13.0±3.1 | |
No. females: males | 8:12 | 4:8 | 18:26 | |
No. MZ:DZ twin pairs‡ | 3:4 | 5:1 | 9:10 | |
ASD twin | Co-twin | |||
Average birth weight in grams (±s.d.) | 2,116.6±872.6 | 2,207.7±773.1 | 2,492.7±495.7 | 2,433.7±761.5 |
ADOS-2 severity score | 4.1±1.8 | 2.2±2.2 | 6.1±2.8 | 2.0±1.6 |
SRS-2 total raw score | 74.1±28.6 | 32.3±25.4 | 98.7±16.2 | 41.9.±32.3 |
Full scale Intelligence Quotient | 93.1±19.0 | 104.2±11.1 | 85.4±21.1 | 99.0±15.3 |
ADOS-2, The Autism Diagnostic Observation Schedule Second Edition; ASD, autism spectrum disorder; DZ, dizygotic; MZ, monozygotic; SRS-2, Social Responsiveness Scale Second Edition.
*Six singletons.
†Six singletons.
‡Singletons excluded.
Data are from 32 full twin pairs and 12 singletons from twin pairs that have participated in the RATSS study.