Table 2

 Case reports and uncontrolled cohort studies linking ADHD with cytogenetic abnormalities in selected groups of children

CitationStudy groupStudy typeOutcomeKey resultsComments
Gothelf et al (2004)7This study investigated the association of familial, developmental, and physical factors with the occurrence of ADHD in 51 patients with non-familial VCFSRetrospective review (level 4)Percentage of patients with a diagnosis of ADHDTwenty one patients (41.2%) were diagnosed with ADHD. There was a significantly greater prevalence of ADHD in the first-degree relatives of the patients with ADHD than in those withoutFindings indicate that ADHD in VCFS has a genetic contribution and the patients’ VCFS related developmental factors and physical illnesses play a lesser role
Boycott et al (2003)8A mother and two sonsCase report (level 4)Chromosomal deletionTerminal deletion of the short arm of the X chromosome (Xp22.3). Both sons had ADHD and learning disabilityOne or more genes involved in learning and attention may reside in Xp22.3
Niklasson et al (2002)9Twenty children and young adults (age range 5–33 years, 12 females and eight males) with genetically confirmed 22q11 deletion syndromeUncontrolled cohort (level 4)No of patients with ADHDIn 13 individuals, attention-deficit-hyperactivity disorder (ADHD), mainly inattentive or combined type in most cases, were diagnosedA significant number of patients with 22q11 deletion have ADHD along with the VCFS phenotype
Hagerman et al (1985)10Four boys had physical and cytogenetic features of the fragile X syndromeUncontrolled cohort (level 4)No of patients with ADHDAll four patients demonstrated similar learning difficulties that included hyperactivityThe IQ scores of these patients extended into the normal range
Le Caignec et al (2004)11Single patient with inherited Ring chromosome 8 and ADHDCase report (level 4)Chromosomal abnormalityChild had short stature and mental retardation while family members had normal intelligenceFirst case report with this particular abnormality
Prabhakara et al (2004)12Single patientCase report (level 4)Chromosomal translocation and sex reversal46XX and familial (9;11) (p22;p15.5) translocationAssociated with delayed development and cryptorchidism
Doherty et al (2003)13Two brothersCase report (level 4)Chromosomal abnormalityUnusual Xp; Yq translocation chromosomeAssociated with attention deficit, generalised epilepsy and ichthyosis
Baker et al (2001)14Single patientCase report (level 4)Chromosomal abnormalityChromosome 2 interstitial deletion (del(2)(q14.1q21))ADHD associated with connective tissue laxity
Ruud et al (2005)15Two boysCase report (level 4)Chromosomal abnormality47, XXY karyotypeADHD was diagnosed and stimulant medication used but full criteria were not met on psychological testing