Enhancing emotion recognition in young autistic children with or without attention-deficit/hyperactivity disorder in Hong Kong using a Chinese App version of The Transporters.

TRIAL REGISTRATION: This study was registered with the German Clinical Trials Register - Deutschen Register Klinischer Studien (DRKS) on 23 December 2018. The Trial Registration Number (TRN) is DRKS00016506. LAY ABSTRACT: The Transporters App is an intervention programme with 15 animated episodes that teach emotion recognition skills to autistic children between 4 and 6 years of age. Each episode contains a story depicting social interactions between characters in the form of a vehicle, with human faces grafted on to each of them. Each episode teaches a specific emotion in a story context. Autistic children watched at least three episodes at home for about 15 min daily for a month, with parental guidance. Its automated, home-based format is cost-saving and readily accessible. This study translated The Transporters to a Cantonese-Chinese version. Results showed a significant improvement in emotion recognition following viewing The Transporters in a group of Hong Kong Chinese autistic children, between 4 and 6 years of age, with and without attention-deficit/hyperactivity disorder (n = 48) relative to a control group (n = 24). A non-autistic group (n = 23) showed that the autistic children scored lower in emotion recognition pre-intervention. Post-intervention, the autistic children had improved in emotion recognition to the level of the non-autistic children. The autistic children in the intervention groups also generalized their learning to novel situations/characters not taught within The Transporters. There was no dosage effect, with the standard recommended number of episodes viewed being sufficient to achieve significant improvement. This study confirms the effectiveness of The Transporters for Chinese autistic children and contributes to the literature/practice by expanding the range of applicability of The Transporters to autistic children with attention-deficit/hyperactivity disorder, which is important given the high rate of co-occurrence between autism and attention-deficit/hyperactivity disorder.

Family-based association study of DRD4 gene in methylphenidate-responded Attention Deficit/Hyperactivity Disorder.

The 48-basepair (48-bp) variable number tandem repeat (VNTR) polymorphism in exon 3 of the dopamine receptor D4 gene (DRD4) is implicated in the etiology of attention-deficit/ hyperactivity disorder (ADHD). In particular, ADHD in European-ancestry population is associated with an increased prevalence of the 7-repeat (7R) allele of the exon 3 VNTR. However, it is intriguing to note that the 7R allele has been found to be of very low prevalence in the Chinese general population. In a previous case-control study, our research team had found that the 7R allele was similarly absent in Chinese ADHD children in Hong Kong. Instead, there was an increased prevalence of the 2R allele in Chinese ADHD children. Interestingly, in Asian samples, the 2R allele had been found to be an evolutionary derivative of the 7R allele with equivalent biochemical functionality. So, the finding of an association between ADHD and 2R allele in Chinese population does not exactly contradict the original 7R allele finding in European-ancestry population. However, given the potential pitfall of population stratification in the previous case-control design, this current study tested the 2R allele and ADHD association using a methodologically more rigorous family-based approach on 33 Chinese ADHD probands who had favorable clinical responses to stimulant medication (methylphenidate). Haplotype Relative Risk (HRR) analysis and Transmission Disequilibrium Test (TDT) both showed a significant preferential transmission of the 2R allele from the biological parents to ADHD probands (pone-tailed = 0.038, OR = 2.04; pone-tailed = 0.048, OR = 2.29, respectively). A second hypothesis speculates that it is the deviation, including 7R and 2R alleles, from the conserved ancestral 4R allele which confers risk to ADHD. Thus, a preferential transmission of non-4R alleles, against the 4R allele, from biological parents to their ADHD probands is predicted. Both HRR analysis and TDT confirmed such prediction (pone-tailed = 0.029, OR = 2.07; pone-tailed = 0.032, OR = 2.43, respectively). This study re-confirmed the original finding of a previous study that in Chinese population, the 2R allele of the DRD4 exon 3 VNTR was related to ADHD. This endorses the general thesis that DRD4 exon 3 VNTR polymorphism is related to ADHD, despite that the exact length or number of repeats of the associated alleles varies across ethnicity. This in turn supports the dopamine dysregulation theory of ADHD.