Assessment and diagnosis of developmental dyslexia in Japanese-English bilingual children : A case series study

Abstract

  Objective: Reading and writing difficulties in children with a multilingual background are often considered to be a consequence of limited language proficiency rather than developmental dyslexia (DD) or intellectual disabilities. However, since these latter conditions are also prevalent in a multilingual population, the present study explored the assessment and diagnosis of DD, through a case-series study of Japanese-English bilingual children. Methods: The participants were four school-aged Japanese-English bilingual children (Cases 1-4) with reading and writing difficulties as a major complaint. They were tested for cognitive abilities (IQ) and both oral language and basic literacy skills in Japanese and English, and we made a diagnosis of a specific learning disorder based on DSM-5. Results: Full-scale IQ and oral language abilities in both Japanese and English were within the normal range for all cases. Regarding basic literacy skills, three of them (Cases 1, 3, 4) showed difficulties from the level of Hiragana reading while one (Case 2) showed difficulties in kanji. Two children who used English at school also showed severe difficulties in alphabet naming (Case 3) and oral text reading (Cases 3, 4). Based on these results, Cases 1, 3, and 4 were diagnosed as having a specific learning disorder in both reading and writing, while Case 2 was diagnosed as having a disorder mainly in writing. Conclusions: The evaluation of basic literacy skills (e. g., letter, word, and simple text reading) were shown to be particularly useful for assessing DD in multilingual children. While assessment and diagnosis in similar cases that involve multiple languages pose many challenges in practice, approaches that can be used to identify innate specific learning disorders despite the complex environmental and linguistic background are needed.