An Investigation Into Etiological Pathways of DCD and ADHD Using a Monozygotic Twin Design

Abstract

W e previously described a co-twin control design using questionnaire data on monozygotic twins discordant and concordant for developmental coordination disorder (DCD) and attention deficit hyperactivity disorder (ADHD). Our results suggested that DCD and developmental ADHD had different causal pathways, and that second-born twins were at higher risk for oxygen perfusion problems than first-born twins. In the current study we further explored our findings using DNA confirmed zygosity and assessments of 4 female and 10 male sets of monozygotic twins, aged 8 to 17 years, from the first study. Using the McCarron Assessment of Neuromuscular Development (MAND), twice as many second-as first-born twins met criteria for DCD. Second-born twins attained significantly lower scores on 1-minute Apgar, MAND Gross Motor, Bimanual Dexterity and Neuromuscular Development Index. Seven of the nine twins who met criteria for DCD experienced perinatal oxygen perfusion problems. This supported findings in the first study of an association between perinatal oxygen perfusion problems and DCD, and our hypothesis that DCD and cerebral palsy have similar causal pathways. We found similar numbers of males and females discordant for DCD. On telephone interview using the Diagnostic Interview Schedule for Children Parent Interview, the only first-, and all five second-born twins who met criteria for ADHD had an inattentive component -three Inattentive; three Combined. All twins positive for ADHD were male. This adds support to our hypothesis that ADHD symptoms found in some participants may reflect secondary ADHD associated with environmental factors, rather than developmental ADHD.

Impact of Cerebral Visual Impairments on Motor Skills: Implications for Developmental Coordination Disorders

“…As noted by Martin et al (2010) , a variety of neurological aetiologies have been suggested for DCD, including pre-, peri-, and post-natal complications ( Kaplan and Sadock, 2007 ; Pearsall-Jones et al, 2009 ), perceptuo-motor organization ( Lord and Hulme, 1988 ), and parietal lobe dysfunction ( Wilson et al, 2004 ). However, as Vaivre-Douret et al (2016) emphasize, the etiology of DCD appears confused on account of the umbrella term of motor dysfunction.…”

Developmental coordination disorder and overweight and obesity in children: a systematic review

“…Lichtenstein et al . found that DCD may have a genetic component, and also perinatal oxygen perfusion problems are associated with the disorder .…”

Coordination difficulty and internalizing symptoms in adults: A twin/sibling study

“…The remaining variance in coordination difficulty was largely due to non-shared environmental influences, and future research focused on identifying these environmental factors may inform targeted clinical and resilience interventions. These factors might include reduced physical activity, as reported in both adults (Hill and Brown, 2013) and children with DCD (Rivilis et al, 2011), unemployment in adults (Kirby et al, 2013 and pre-and perinatal complications (Pearsall-Jones et al, 2008;Pearsall-Jones et al, 2009). The impact of environmental influences on coordination may also happen via epigenetic mechanisms, which involve changes in gene expression that play a role in a range of neurological disorders (Jakovcevski and Akbarian, 2012;Urdinguio et al, 2009) and these processes should be explored in future studies.…”