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Table 1 Demographic information on the sample by diagnosis and concordance for 58 twin pairs

From: Minor physical anomalies in neurodevelopmental disorders: a twin study

  TD ASD ADHD NDD
Concordant Concordant Discordant Concordant Discordant Concordant Discordant
Number of pairs 19 8 12 13 11 22 17
Zygosity by pairs (MZ:DZ) 18:1 8:0 10:2 12:1 7:4 19:3 14:3
Sex by twin (female:male) 21:17 6:10 9:15 8:18 8:14 10:34 19:15
Age, mean 15.26 13.88 13.50 13.69 13.00 14.14 12.59
    Affected twin Co-twin   Affected twin Co-twin   Affected twin Co-twin
IQ, mean 103.37 83.44 91.25 97.92 86.85 101.27 97.27 86.52 94.82 97.94
(SD, range) (13.80, 81–138) (16.73, 58–110) (18.78, 69–121) (17.20, 65–121) (14.56, 64–110) (11.22, 84–121) (9.98, 85–121) (15.72, 58–115) (16.16, 70–121) (11.50, 77–121)
SRS-2, total raw mean 18.47 89.81 87.75 36.42 79.77 56.91 32.18 70.68 57.53 25.82
(SD, range) (14.58, 0–65) (33.30, 38–141) (27.02, 41–130) (23.29, 8–93) (37.27, 33–142) (34.35, 15–117) (15.57, 14–55) (38.10, 14–142) (33.78, 3–117) (13.19, 8–51)
# Participants with other diagnoses
 ASD: n (%)   16 (100.00) 12 (100.00) 0 (0.00) 12 (46.15) 4 (36.36) 1 (9.09) 19 (43.18) 9 (52.94)  
 ADHD: n (%) 0 (0.00) 11 (68.75) 5 (41.67) 2 (16.67) 26 (100.00) 11 (100.00) 0 (0.00) 30 (68.18) 7 (41.17) 0 (0.00)
 ID: n (%) 0 (0.00) 4 (25.00) 1 (8.33) 1 (8.33) 4 (15.38) 0 (0.00) 0 (0.00) 8 (18.18) 1 (5.88) 0 (0.00)
 Other NDD: n (%) 0 (0.00) 7 (43.75) 5 (41.67) 1 (8.33) 12 (46.15) 4 (36.36) 3 (27.27) 23 (52.27) 7 (41.17) 0 (0.00)
  1. Demographic findings for the sample by TD or diagnosis and concordance of diagnosis. Means, standard deviations, and ranges are used to describe demographic data related to the participants. Participants may be represented in more than one column in the table if they have concurrent diagnoses (e.g., diagnosis of both ASD and ADHD). Examples of other NDDs include communication disorder, specific learning disorder, motor disorder, or other neurodevelopmental disorders
  2. MZ monozygotic, DZ dizygotic, SD standard deviation, IQ intelligence quotient, ASD autism spectrum disorder, ADHD attention-deficit/hyperactivity disorder, ID intellectual disability, NDD neurodevelopmental disorder