ICD-116A03	DEVELOPMENTAL LEARNING DISORDER Developmental learning disorder
ICD-10F81	Specific developmental disorders of scholastic skills
DSM-5-TRF81.0	Specific Learning Disorder, With Impairment in Reading

1. Definition and nosology

Specific learning disability (ICD-11: 6A03 Developmental Learning Disorder; DSM-5-TR: F81.0–F81.81 Specific Learning Disorder) — a neurodevelopmental disorder manifesting with persistent and significant difficulties in acquiring one or more academic skills, unexpected given the patient's age, intellectual level, and educational opportunities.

Subspecifications in ICD-11:

• 6A03.0 — with reading impairment (dyslexia);
• 6A03.1 — with written expression impairment (dysgraphia);
• 6A03.2 — with impaired mathematics (dyscalculia);
• 6A03.3 – other specified or combined.

2. History

• Pringle Morgan W. (1896) — “congenital word blindness” – describes a child who cannot read despite normal intelligence.
• Orton S.T. (1925) — The concept of “strephosymbolia”; hypothesized a weakness of left hemisphere dominance; the foundation of the Orton-Gillingham method.
• DSM-III (1980) — Specific Developmental Disorder Category — Based on IQ-academic skill discrepancy model.
• DSM-5 (2013) — elimination of the discrepancy model: “Specific Learning Disorder” — no IQ cutoff required; persistent functional difficulty and unresponsiveness to intervention are the basis. Separate coding of subtypes (reading, writing, mathematics) is retained.
• ICD-11 (2019) — parallel structure; with the term “Developmental Learning Disorder”.
• Phonological deficit theory (Stanovich K.E., Snowling M.J., Vellutino F.R.) — became dominant in the 1990s–2000s as the core mechanism of dyslexia.

3. Epidemiology

• General prevalence: School-age children: 5–15% (DSM-5-TR estimate); varies depending on the country and the orthographic depth of the language (the prevalence is higher in languages with deep orthographies, such as English).
• Dyslexia: 5–10% in school-age children; the most prevalent subtype.
• Dyscalculia: 3–7% (Shalev R.S. Pediatr Neurol 2007 review).
• Dysgraphia: 4–7% (Berninger V.W. Top Lang Disord 2008).
• Sex: In reading and writing disorders, boys are 2–3 times higher (the hypothesis of underdiagnosis in females exists); in math disorder, genders are equal.
• Comorbidity: ADHD 30–40%, language disorders 50–60% (in reading disorder), increased risk of anxiety, depression, conduct disorders.

4. Aetiology and pathogenesis

4.1 Genetic factors

• Heritability: in dyslexia 50–70% (Pennington B.F. Cogn Neuropsychol 2002 twin study review).
• Identified risk genes: DYX1C1 (15q21), KIAA0319 (6p22), DCDC2 (6p22), ROBO1 (3p12) — associated with neural migration and cortex formation; however, not a single gene, but a polygenic risk architecture.
• In mathematical disorder, high heritability (~70%), MYT1L and other genes are proposed (Mascheretti S. et al. Trends Genet 2018).

4.2 Neurobiological mechanisms

• Dyslexia — phonological deficit: in left perisylvian areas (Wernicke, angular gyrus, superior temporal gyrus) atypical activation patterns (Shaywitz S.E., Shaywitz B.A. Biol Psychiatry 2008 fMRI review). Deficit in phoneme-grapheme (sound-letter) correspondence is the core of reading difficulty.
• Dyscalculia — number sense (approximate number system) and working memory: functional disruption in intraparietal sulcus and prefrontal cortex (Butterworth B. Trends Cogn Sci 2010).
• Dysgraphia: motor planning and orthographic coding deficits; left fusiform and premotor areas.

4.3 Environmental factors (modifier)

• Early educational quality and reading instruction methodology — lack of phonological approach creates greater academic disparity in children with polygenic risk.
• Low socioeconomic status — not etiology, but a factor in identification and access to intervention.
• Chronic otitis media — may affect early phonological development.

5. Clinical features

5.1 Reading disorder (dyslexia, 6A03.0)

• Inaccuracy and slowness in word reading — reads words slowly, with struggle, substitutes or omits letters.
• Phonological awareness deficit — difficulty with rhyming, letter-sound correspondence, segmenting words into sounds.
• Writing and spelling — phonetic rule non-conforming writing errors.
• Reading comprehension — secondary impairment due to word recognition deficit.
• Early signs (preschool) — delayed learning of letter names, difficulty with rhyming games, difficulty reading names.

5.2 Written expression disorder (dysgraphia, 6A03.1)

• Handwriting is poor, illegible, slow.
• Difficulty in sentence construction, grammar, and paragraph organization.
• Persistent errors in spelling and punctuation.
• Large discrepancy between written and oral expression skills.

5.3 Mathematics disorder (dyscalculia, 6A03.2)

• Number sense deficit — quantitative comparison, assessment of magnitude.
• Difficulty recalling mathematical facts (e.g., multi-digit multiplication table).
• Slowness and errors in mathematical operations — addition, subtraction, multi-step problems.
• Difficulties in the verbal presentation of mathematical problems.

6. Diagnosis

6.1 Unified diagnostic criteria (DSM-5-TR · ICD-11 consensus points)

A. Persistent difficulties in the acquisition and use of academic skills — persists for at least 6 months despite age-appropriate targeted intervention. At least one of the following symptoms:

1. Inaccuracy or slowness in reading words;
2. Difficulty understanding the text being read;
3. Spelling difficulties;
4. Difficulties in written expression (grammar, punctuation, organization);
5. Challenges in emotional and cognitive skills;
6. Difficulties in mathematical reasoning.

B. Academic skills are significantly below the age-expected level — documented by standardized tests (-1.5 SD or lower for chronological age), creates functional impairment in academic or occupational activity.

C. Onset at school age (but may not fully manifest until academic demands increase).

D. Exclusions — Not fully explained by intellectual disability, hearing/vision deficit, other neurological or psychiatric condition, psychosocial deprivation, ambiguity in academic language of instruction, inadequate education.

6.2 Source-specific clarifications

• DSM-5-TR: The “IQ-academic ability discrepancy” model has been abolished — no IQ cutoff is required for diagnosis; unresponsiveness to long-term intervention is essential. Severity: mild, moderate, severe — based on adaptive functioning.
• ICD-11 (6A03): Parallel structure; sub-specifications (reading, writing, math). Severity is not a separate qualifier.
• IDA — International Dyslexia Association: dyslexia — neurobiological origin, deficit in phonological processing; ‘neuroinformation-processing’ disorder. Standardized literacy assessment + response observation (Response to Intervention, RTI) recommended.
• AAP Clinical Report on Dyslexia (Handler S.M., Fierson W.M. Pediatrics 2011, reaffirmed): diagnosis should be referred by pediatricians, assessment multidisciplinary — psychologist + speech-language pathologist + educational specialist.
• NICE: no specific clinical guidelines for learning disorder; main framework is within the education system (SEND Code of Practice, EHCP).

6.3 Diagnostic algorithm

1. Teacher and parent interview — academic history, response to intervention.
2. Visual and hearing tests (to rule out sensory impairment).
3. Standardized academic achievement tests — Woodcock-Johnson IV, WIAT-4, KTEA-3.
4. Phonological awareness and reading assessment — CTOPP-2, GORT-5, TOWRE-2.
5. For mathematics — KeyMath-3, TEMA-3.
6. Intellectual assessment (WISC-V) — except for intellectual disability; discrepancy not necessary for diagnosis.
7. Assessment of attention, executive function (BRIEF-2), working memory.
8. Response to Intervention (RTI) documentation — persistent difficulty despite ≥ 6 months of age-appropriate intervention.
9. Comorbidity screening — ADHD, language disorder, anxiety, depression.

6.4 Differential diagnosis

7. Examination and assessment

7.1 Standardized tests

• Academic skills: Woodcock-Johnson IV (comprehensive), WIAT-4 (Wechsler Individual Achievement Test), KTEA-3.
• Reading: GORT-5 (Gray Oral Reading Test), TOWRE-2 (Test of Word Reading Efficiency), CTOPP-2 (Comprehensive Test of Phonological Processing).
• Mathematics: KeyMath-3, TEMA-3 (Test of Early Mathematics Ability).
• Intellect and cognition: WISC-V, WJ-IV Cognitive.
• Executive function: BRIEF-2 (parent/teacher questionnaire).
• Working memory, processing speed: WISC-V indices, digit span, Trail Making.

7.2 Laboratory investigations

No routine laboratory indication. Based on specific clinical suspicion:

• Lead level — if risk factors are present.
• Thyroid function — if congenital hypothyroidism is undetected.
• Genetic research — if comorbid intellectual disability or syndromic features present.

7.3 Instrumental investigations

• Brain MRI — no routine indication; in case of focal neurological signs, seizures, regression.
• EEG — suspected seizure, rule out Landau-Kleffner.
• Hearing test and vision test — mandatory initial assessments in all cases.

8. Treatment

8.1 General principles (IDA · AAP 2011 · APA · NASP consensus)

1. Specific learning disorders are not treated pharmacologically. Intervention — evidence-based education and therapy.
2. Early identification and intervention — intervention efficacy is significantly higher in preschool and early school-age periods. RTI (Response to Intervention) model — age-appropriate intervention stepwise, lack of response leads to diagnostic assessment.
3. Dyslexia — Structured Literacy approach: systematic, sequential, explicit, multisensory, diagnostic training. Phonological awareness + phoneme-grapheme correspondence + word structure + syntax + semantics. Orton-Gillingham, Wilson Reading System, Lindamood-Bell are typical programs.
4. Dyscalculia: Concrete-Representational-Abstract (CRA) instruction; number sense development, math fact memorization exercises.
5. Dysgraphia: Handwriting training (e.g., Handwriting Without Tears), keyboard learning, word-sentence organization strategies, voice-to-text technology.
6. Academic accommodations: Extra time, audiobooks, keyboard, text-to-speech software, calculator in math — within IEP / EHCP.
7. Treatment of comorbidity: ADHD — stimulants; anxiety and depression — CBT; language disorder — SLP.
8. Social-emotional support. Children with learning disorders are at high risk for issues related to self-esteem, motivation, and anxiety.

8.2 Source-specific clarifications

• IDA Knowledge and Practice Standards for Teachers of Reading (2018): Structured Literacy framework; certified teacher requirement.
• AAP 2011 (Handler & Fierson): dyslexia biologically based; academic intervention first-line; visual therapy is contraindicated (see 10.3).
• National Reading Panel (NRP) 2000: five essential reading components — phonological awareness, phonics, fluency, vocabulary, comprehension.
• NASP (National Association of School Psychologists): Within RTI, there are three tiers — universal screening, targeted intervention, and intensive individualized intervention.

Treatment methods

1. Orton-Gillingham (OG) approach — Structured multisensory phoneme-grapheme-based reading and spelling training. First-line methodology for dyslexia; conducted by certified teacher/therapist. Evidence: Stevens E.A. et al. J Learn Disabil 2021 meta-analysis — medium effect size in reading and spelling. Academy of Orton-Gillingham Practitioners.
2. Wilson Reading System — Program based on Orton-Gillingham principles, a 12-step complex reading and spelling program; from age 6 to adulthood. wilsonlanguage.com.
3. Lindamood-Bell programs — LiPS (Lindamood Phoneme Sequencing) — combines phoneme awareness with motor-kinesthetic component; Seeing Stars — orthographic encoding. lindamoodbell.com.
4. Structured Literacy (IDA Knowledge and Practice Standards) — Not a specific program, a framework — systematic, sequential, explicit, multisensory, diagnostic teaching principles. Orton-Gillingham, Wilson, Lindamood-Bell and others fit this framework. dyslexiaida.org.
5. Concrete-Representational-Abstract Instruction (CRA) — For dyscalculia — training starting with concrete manipulative tools, then pictorial representation, then transitioning to abstract symbolic operations. Evidence: Witzel B.S. et al. J Spec Educ Technol 2003.
6. “Handwriting Without Tears” program — Olsen (Olsen J.) — Multisensory handwriting training program used in dysgraphia and writing difficulties. lwtears.com.
7. Response to Intervention (RTI) / Multi-Tiered System of Supports (MTSS) — 3-tier framework – Tier 1: universal high-quality training; Tier 2: targeted small group intervention; Tier 3: intensive individual intervention. Established by IDEA 2004 law in USA; similar frameworks in other countries.
8. Assistive Technology — Text-to-speech (Read&Write, NaturalReader), speech-to-text (Dragon Naturally Speaking), audiobooks (Bookshare, Learning Ally), calculation tools for math — functional compensation. Recommended by AAP and IDA.
9. Comprehensive Test of Phonological Processing (CTOPP-2) — Standardized assessment of phonological awareness — gold standard in dyslexia identification.
10. GORT-5 (Gray Oral Reading Test) and TOWRE-2 — Measurement of reading speed, accuracy, and fluency.

9. Prognosis

Good prognostic factors

• Early identification (preschool or early school age).
• Evidence-based Structured Literacy intervention.
• High IQ — development of compensatory strategies.
• Family support and motivation.
• Affects only one academic domain (e.g., single reading, math normal).

Poor prognostic factors

• Late identification (middle or late school age).
• The impact across multiple academic domains.
• Comorbid ADHD, language disorder, anxiety.
• Low socioeconomic support, limited educational resources.
• Intervention with unproven methods (colored lenses, visual therapy, Brain Gym).

Follow-up targets

• Academic achievement monitoring — annual standardized tests.
• Social-emotional health — self-esteem, anxiety, depression screening.
• Separate intervention for comorbid ADHD and language disorder.
• Professional and academic accommodation planning in adulthood (disability-related opportunities in higher education, workplace adaptation).
• Enhancement of assistive technology use (text-to-speech, calculator).

10. Myths and misconceptions

10.1 Aetiology myths

Myth 1: “Dyslexia is the result of a child's laziness or poor upbringing”

Why it is widespread: Belief “if they try hard enough, they can read”; incorrect explanation of academic struggle as a character issue.

Clinical and biological rationale: Dyslexia — neurobiological It is a disorder. fMRI studies (Shaywitz S.E. Biol Psychiatry 2008) have shown atypical activation patterns in left perisylvian areas; heritability 50–70%, identified risk genes (DYX1C1, KIAA0319, DCDC2). The patient is forced to expend higher cognitive effort rather than work harder — this leads to chronic exhaustion.

Evidence: IDA Definition (2002, update) — “Dyslexia is a specific learning disability of neurobiological origin.”

Real clinical step: Explain biological basis to family; evidence-based Structured Literacy intervention and academic accommodation instead of blaming.

Myth 2: “Dyslexia is children writing letters in reverse (mirror)”

Why it is widespread: Orton 1925 ‘strephosymbolia’ term and recurring image in popular media.

Clinical and biological rationale: Reversed letter writing and reading is normal in all children aged 4–7 years; persistent letter inversion after age 8 may raise clinical suspicion, but of dyslexia Not main symptom. The core of dyslexia is a deficit in phonological processing.

Evidence: Stanovich K.E. (2000) — phonological deficit theory; visual-spatial deficit is not primary etiology.

Myth 3: “Children with dyslexia will ‘outgrow it’ with age, no intervention needed”

Evidence: Bruck M. Dev Psychol 1992 — long-term follow-up studies: dyslexic children without intervention retain reading difficulties in adulthood; academic and vocational outcomes are poor. The earlier the intervention, the higher the compensation potential.

10.2 Harmful or scientifically unfounded methods

Myth 4: “Colored lenses (Irlen lenses) or colored overlays cure dyslexia”

Why it is widespread: In the 1980s, concept of ‘scotopic sensitivity syndrome’ by Helen Irlen; marketing by commercial optometric clinics.

Evidence: AAP, AAO (American Academy of Ophthalmology) and AAPOS (American Association for Pediatric Ophthalmology and Strabismus) 2009 and 2014 Joint Statements: The effect of colored lenses and overlays for dyslexia is unproven; Cochrane (Evans B.J., Allen P.M. 2016) systematic review — insufficient evidence of effect. AAP — delays first-line intervention (Structured Literacy).

Real clinical step: Clear explanation to family; evidence-based phonological reading program as intervention.

Myth 5: “Visual therapy (eye exercises) cures dyslexia”

Evidence: AAP, AAO, AAPOS 2009 Joint Statement — emphasizes dyslexia is a language-based disorder, not an eye movement disorder; effect of eye exercises on reading performance not proven. Visual therapy is indicated only for specific eye movement disorders (e.g., convergence insufficiency).

Myth 6: “Brain Gym / Educational Kinesiology”

Evidence: Hyatt K.J. Remedial Spec Educ 2007 systematic review — claims do not align with neurobiology; no effect on academic achievement. Criticized as a conversion program.

Myth 7: “Cerebellar Exercise Therapy”

Why it is widespread: Wynford Dore popularized in the 2000s a theory linking cerebellar function to reading; claims of “positive outcomes” attracted media attention.

Evidence: The original research by Reynolds D., Nicolson R.I. received rigorous methodological criticism (Bishop D.V. Dyslexia 2007); the effect was not confirmed in subsequent studies. British Dyslexia Association — does not recommend the Dore programme.

10.3 Ineffective methods or those delaying primary intervention

Myth 8: “Whole Language” approach teaches reading instead of phonics

Evidence: National Reading Panel 2000 (NRP) — systematic phonics instruction openly dominant From “whole language” approach, especially in children with learning difficulties. Same position incorporated into educational legal standards by Endrew F. v. Douglas County (US Supreme Court 2017). The “Reading Wars” debate has largely been resolved in favor of systematic phonics.

Myth 9: Auditory Integration Training (AIT) / Tomatis method cures dyslexia

Evidence: ASHA Position Statement 2004 — AIT has not been proven effective for dyslexia or learning disorders.

Myth 10: “EEG Neurofeedback cures dyslexia or dyscalculia”

Evidence: Neurofeedback effect for specific learning disorder has not been proven. Modest effect in ADHD (Holtmann 2011), but extrapolation to learning disorders is unfounded.

Myth 11: “Special diet (gluten-free, omega-3 mega-dose, ‘brain food’) cures dyslexia”

Evidence: Cochrane and systematic reviews (Tan M.L. et al. J Pediatr 2012 for omega-3) — sustained clinical effect in dyslexia has not been proven. Some studies have shown a small effect, but methodological limitations exist.

Myth 12: “Hyperbaric oxygen chamber (HBOT) or stem cell injections”

Evidence: No proven effect for specific learning disorder; risk profile is significant (HBOT — pneumothorax; stem cells — infection, fatal cases).

11. Sources

1. WHO. ICD-11 for Mortality and Morbidity Statistics. 6A03 Developmental learning disorder. 2024.
2. American Psychiatric Association. DSM-5-TR. Washington DC: APA Publishing; 2022.
3. International Dyslexia Association. Definition of Dyslexia. 2002, updated. dyslexiaida.org.
4. IDA Knowledge and Practice Standards for Teachers of Reading. 2018.
5. Handler S.M., Fierson W.M., American Academy of Pediatrics Section on Ophthalmology, Council on Children with Disabilities. Joint Technical Report — Learning Disabilities, Dyslexia, and Vision. Pediatrics 2011;127(3):e818–e856.
6. National Reading Panel. Teaching Children to Read: An Evidence-Based Assessment of the Scientific Research Literature on Reading and Its Implications for Reading Instruction. NIH; 2000.
7. Pennington B.F. From single to multiple deficit models of developmental disorders. Cogn Neuropsychol 2002;19(5):385–414.
8. Shaywitz S.E., Shaywitz B.A. Paying attention to reading: The neurobiology of reading and dyslexia. Biol Psychiatry 2008;63(3):219–225.
9. Butterworth B. Foundational numerical capacities and the origins of dyscalculia. Trends Cogn Sci 2010;14(12):534–541.
10. Shalev R.S. Prevalence of developmental dyscalculia. Pediatr Neurol 2007;37(6):385–391.
11. Berninger V.W., Niedo J. Aphasia and apraxia of speech in adults vs. dyslexia and dysgraphia in children. Top Lang Disord 2008;28(2):143–153.
12. Stevens E.A., Austin C., Moore C. et al. Current state of the evidence: Examining the effects of Orton-Gillingham reading interventions for students with or at risk for word-level reading disabilities. J Learn Disabil 2021;54(6):399–414.
13. Bruck M. Persistence of dyslexics' phonological awareness deficits. Dev Psychol 1992;28(5):874–886.
14. American Academy of Pediatrics, American Academy of Ophthalmology, American Association for Pediatric Ophthalmology and Strabismus. Joint Statement — Learning Disabilities, Dyslexia, and Vision. Pediatrics 2009;124(2):837–844.
15. Evans B.J., Allen P.M. A systematic review of controlled trials on visual stress using Intuitive Overlays or the Intuitive Colorimeter. J Optom 2016;9(4):205–218.
16. Witzel B.S., Mercer C.D., Miller M.D. Teaching algebra to students with learning difficulties: an investigation of an explicit instruction model. J Spec Educ Technol 2003;18(3):27–34.
17. Hyatt K.J. Brain Gym: building stronger brains or wishful thinking? Remedial Spec Educ 2007;28(2):117–124.
18. Bishop D.V.M. Curing dyslexia and attention-deficit hyperactivity disorder by training motor co-ordination: Miracle or myth? Dyslexia 2007;13(1):4–7.
19. Tan M.L., Ho J.J., Teh K.H. Polyunsaturated fatty acids (PUFAs) for children with specific learning disorders. Cochrane Database Syst Rev 2012;(12):CD009398.
20. Olsen J.Z. Handwriting Without Tears. Cabin John: Handwriting Without Tears, 2008.
21. Reynolds D., Nicolson R.I., Hambly H. Evaluation of an exercise-based treatment for children with reading difficulties. Dyslexia 2003;9(1):48–71.
22. Snowling M.J., Hulme C. A critique of claims from Reynolds, Nicolson & Hambly (2003) that DDAT is an effective treatment for children with reading difficulties. Dyslexia 2003;9(2):127–133.