OBJECTIVE: The prevalence of attention deficit/hyperactivity disorder (ADHD) in school-age children is 7.2%, and ADHD is divided into clinical subtypes. METHODS: The current study explored whether specific cognitive profiles as assessed using the Wechsler Intelligence Scale for Children (WISC)-IV could be obtained for each clinical ADHD subtype (ADHD-Inattentive type and ADHD-Combined type) and investigated the correlation between WISC scores and parental age at their children’s birth or birthweight. The enrolled sample comprised 12 ADHD-I and 15 ADHD-C subjects. RESULTS: An impaired Processing Speed Index was found in ADHD-I. The age of the father at the child’s birth and birthweight positively correlated with the full scale intelligence quotient (FSIQ) score in the WISC assessment. CONCLUSION: Inattentiveness within the behaviors of the children with ADHD-I is partly due to the impaired processing speed, therefore effective support for ADHD will be conducted if educator decreases their speaking speed. Since biological basis of ADHD is still largely unknown, future studies using both psychological and biological methods will reveal the etiology of ADHD. These scientific assessments will provide information for more effective approaches in the care of children with ADHD.
Child ; Cognitive Science ; Fathers ; Humans ; Intelligence ; Neurodevelopmental Disorders ; Parents ; Parturition ; Prevalence

Kawasaki disease (KD) is an acute febrile vasculitis predominately affecting infants and children. The dominant incidence age of KD is from 6 months to 5 years of age, and the incidence is unusual in those younger than 6 months and older than 5 years of age. We tried to identify genetic variants specifically associated with KD in patients younger than 6 months or older than 5 years of age. We performed an age-stratified genome-wide association study using the Illumina HumanOmni1-Quad BeadChip data (296 cases vs. 1,000 controls) and a replication study (1,360 cases vs. 3,553 controls) in the Korean population. Among 26 candidate single nucleotide polymorphisms (SNPs) tested in replication study, only a rare nonsynonymous SNP (rs4365796: c.1106C>T, p.Thr369Met) in the lymphoid enhancer binding factor 1 (LEF1) gene was very significantly associated with KD in patients younger than 6 months of age (odds ratio [OR], 3.07; p(combined) = 1.10 × 10⁻⁵), whereas no association of the same SNP was observed in any other age group of KD patients. The same SNP (rs4365796) in the LEF1 gene showed the same direction of risk effect in Japanese KD patients younger than 6 months of age, although the effect was not statistically significant (OR, 1.42; p = 0.397). This result indicates that the LEF1 gene may play an important role as a susceptibility gene specifically affecting KD patients younger than 6 months of age.
Asian Continental Ancestry Group ; Child ; Genome-Wide Association Study ; Humans ; Incidence ; Infant ; Lymphoid Enhancer-Binding Factor 1 ; Mucocutaneous Lymph Node Syndrome* ; Polymorphism, Single Nucleotide ; Vasculitis