Sibling Recurrence Risk and Cross-aggregation of Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder

Abstract

IMPORTANCE Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are believed to partially share genetic factors and biological influences. As the number of children with these diagnoses rises, so does the number of younger siblings at presumed risk for ADHD and ASD; reliable recurrence risk estimates within and across diagnoses may aid screening and early detection efforts and enhance understanding of potential shared causes. OBJECTIVE To examine within-diagnosis sibling recurrence risk and sibling cross-aggregation of ADHD and ASD among later-born siblings of children with either disorder. DESIGN, SETTING, AND PARTICIPANTS Using data extracted from medical records of 2 large health care systems in the United States, estimates of recurrence risk and cross-aggregation in later-born siblings of children with ADHD or ASD were compared with later-born siblings of children without these diagnoses. One data set included children seen between January 1, 1995, and December 31, 2013; the other included children born between January 1, 1998, and May 17, 2010. Participants included 15 175 later-born siblings of children with ADHD, ASD, and no known diagnosis. The study was conducted from October 2, 2017, to August 14, 2018. MAIN OUTCOMES AND MEASURES Diagnoses of ASD or ADHD in the later-born sibling, ascertained from medical records, were the primary outcomes of interest; moderators included sex, gestational age, and maternal age. RESULTS A total of 15 175 later-born siblings were classified by familial risk status based on the older child’s diagnostic status: ADHD risk (n = 730; male [51.92%]), ASD risk (n = 158; male [48.10%]), and no known risk (n = 14 287; male [50.73%]). Compared with later-born siblings of children without ADHD or ASD, later-born siblings of children with ASD were more likely to be diagnosed with ASD (odds ratio [OR], 30.38; 95% CI, 17.73–52.06) or ADHD in the absence of ASD (OR, 3.70; 95% CI, 1.67–8.21). Compared with later-born siblings of children without a diagnosis, later-born siblings of children with ADHD were more likely to be diagnosed with ADHD (OR, 13.05; 95% CI, 9.86–17.27) or ASD in the absence of ADHD (OR, 4.35; 95% CI, 2.43–7.79). CONCLUSIONS AND RELEVANCE Later-born siblings of children with ASD or ADHD appear to be at elevated risk for the same disorder, but also of being diagnosed with the other disorder. These findings provide further support for shared familial mechanisms underlying ASD and ADHD, which may be useful for genetic and prospective developmental studies. Later-born siblings of children with ADHD or ASD should be monitored for both conditions.

Inattention and hyperactive/impulsive component scores do not differentiate between autism spectrum disorder and attention-deficit/hyperactivity disorder in a clinical sample

“…One possible explanation for the co-occurrence between ASD and ADHD is that they share common etiologies [7]. Evidence for shared genetic liability is supported by family and twin studies [8,9], alongside general population studies [10,11]. Twin studies have also examined the correlations between specific ASD and ADHD domains, and found a high genetic correlation between restricted repetitive behaviors and interests (RRBI) and domains of inattention and hyperactivity/impulsivity [9,12,13], and between social-communication and hyperactivity/impulsivity [10].…”

Early Motor Differences in Infants at Elevated Likelihood of Autism Spectrum Disorder and/or Attention Deficit Hyperactivity Disorder

“…Infants with an older sibling with ASD have an approximately 20% chance of developing ASD themselves (Ozonoff et al 2011; see Jones et al 2014). Recurrence rates of ADHD in similar designs have been less well characterised, but estimates of heritability are similar for both conditions (see Wade et al 2015;Musser et al 2014;Miller et al 2019). We tested whether increased familial likelihood of ASD and/or ADHD influences the development of midline crossing behaviours in a naturalistic reaching task.…”

ADHS und hochfunktionale Autismus-Spektrum-Störungen

“…So fanden sich bei 10,4 % der Mütter und 11,3 % der Väter deutliche Hinweise auf das Vorliegen einer ADHS [58]. In unterschiedlichen Untersuchungen, die auch Zwillingsstudien umfassen, wurde festgestellt, dass beide Erkrankungen eine hohe Heritabilität und genetische Überschneidungen haben, die sich der dimensionalen Sichtweise entsprechend entweder subklinisch oder in vollem symptomatischen Ausmaß zeigen können [51,[59][60][61].…”

“…Das Risiko für das Vorliegen einer ADHS war ebenfalls deutlich erhöht (adjusted RR, 3,7; 95 %CI, 2,9-4,7), eine ADHS fand sich bei 5,3 % der Geschwisterkinder. 79) im Vergleich mit denjenigen ohne eine diagnostizierte ADHS [59]. Die Studie zeigt insofern eindrücklich, dass nicht nur die Auftretenswahrscheinlichkeiten für die jeweilige Erkrankung erhöht sind, sondern das Risiko durch möglicherweise gemeinsame ätiologische familär-genetische Faktoren für die jeweils andere Erkrankung erhöht ist, was sich in anderen Studien, wenn auch nicht in allen [68,69], zeigte [49,57,61,62,70].…”