According to SpLD Assessment Standards Committee (SASC, 2024), the updated definition of dyslexia is as follows:

• Dyslexia is primarily a set of processing difficulties that affect the acquisition of reading and spelling.

• In dyslexia, some or all aspects of literacy attainment are weak in relation to age, standard teaching and instruction, and level of other attainments.

•  Across languages and age groups, difficulties in reading and spelling fluency are a key marker of dyslexia.

• The nature and developmental trajectory of dyslexia depends on multiple genetic and environmental influences.

•  Dyslexic difficulties exist on a continuum and can be experienced to various degrees of severity.

• Dyslexia can affect the acquisition of other skills, such as mathematics, reading comprehension or learning another language.

• The most commonly observed cognitive impairment in dyslexia is a difficulty in phonological processing (i.e. in phonological awareness, phonological processing speed or phonological memory). However, phonological difficulties do not fully explain the variability that is observed.

• Working memory, orthographic skills and processing speed problems can contribute to the impact of dyslexia and therefore should be assessed.

• Dyslexia frequently co-occurs with one or more other developmental difficulty, including developmental language disorder, dyscalculia, ADHD, and developmental coordination disorder.