Dyslexia-related loci are significantly associated with language and literacy in Chinese-English bilingual Hong Kong Chinese twins.

A recent genome-wide association study on dyslexia in 51,800 affected European adults and 1,087,070 controls detected 42 genome-wide significant single nucleotide variants (SNPs). The association between rs2624839 in SEMA3F and reading fluency was replicated in a Chinese cohort. This study explores the genetic overlap between Chinese and English word reading, vocabulary knowledge and spelling, and aims at replicating the association in a unique cohort of bilingual (Chinese-English) Hong Kong Chinese twins. Our result showed an almost complete genetic overlap in vocabulary knowledge (r2 = 0.995), and some genetic overlaps in word reading and spelling (r2 = 0.846, 0.687) across the languages. To investigate the region near rs2624839, we tested proxy SNPs (rs1005678, rs12632110 and rs12494414) at the population level (n = 305-308) and the within-twin level (n = 342-344 [171-172 twin pairs]). All the three SNPs showed significant associations with quantitative Chinese and English vocabulary knowledge (p < 0.05). The strongest association after multiple testing correction was between rs12494414 and English vocabulary knowledge at the within-twin level (p = 0.004). There was a trend of associations with word reading and spelling in English but not in Chinese. Our result suggested that the region near rs2624839 is one of the common genetic factors across English and Chinese vocabulary knowledge and unique factors of English word reading and English spelling in bilingual Chinese twins. A larger sample size is required to validate our findings. Further studies on the relationship between variable expression of SEMA3F, which is important to neurodevelopment, and language and literacy are encouraged.

Psychometric Evaluation of the Chinese Version of a Weight-Related Eating Questionnaire Using an Item Response Theory Approach.

Valid and reliable measures are needed to identify individuals at risk of dietary restraint, emotional and external eating, and to customize weight loss education for more effective weight management. This study aimed to develop and validate a Chinese version of the Weight-Related Eating Behavior Questionnaire (WREQ-C) for assessing dietary restraint, emotional eating, and external eating. In stage one, the linguistic validation of the original English version of the WREQ (WREQ-E) was conducted. In stage two, the psychometric properties of the WREQ-C were first evaluated by item response theory-based (IRT) analyses. The reduced scale was then examined for convergent validity, structural validity (using a confirmatory factor analysis), population invariance, and test-retest reliability. The study included 1007 adults aged between 18 and 71 years. The IRT analysis optimally shortened the original WREQ-E from 16 to 13 items. A convergent validity analysis showed significant correlations between the WREQ-C subscales and the Chinese version of the Dutch Eating Behavior Questionnaire subscales (r = 0.63-0.82). The 13-item WREQ-C demonstrated good reliability (Cronbach's α = 0.74-0.89) and validity for assessing the psychological aspects of eating behavior, including routine restraint, compensatory restraint, susceptibility to external cues, and emotional eating in Chinese adults.