Dyslexic children require special instruction for word analysis and spelling from an early age. While there are fonts that may help people with dyslexia better understand writing, this might simply be due to the added spacing between words. The prognosis, generally speaking, is positive for individuals who are identified in childhood and receive support from friends and family.

It is generally accepted that DLD is strongly influenced by genetic factors. The best evidence comes from the Twin study method. Two twins growing up together are exposed to the same home environment, yet may differ radically in their language skills. Such different outcomes are, however, much more common in fraternal (non-identical) twins, who are genetically different. Identical twins share the same genes and tend to be much more similar in language ability. There can be some variation in the severity and persistence of DLD in identical twins, indicating that non-genetic factors affect the course of disorder, but it is unusual to find a child with DLD who has an identical twin with typical language.

There was considerable excitement when a large, multigenerational family with a high rate of DLD were found to have a mutation of the FOXP2 gene just in the affected family members. However, subsequent studies have found that, though DLD runs in families, it is not usually caused by a mutation in FOXP2 or another specific gene. Current evidence suggests that there are many different genes that can influence language learning, and DLD results when a child inherits a particularly detrimental combination of risk factors, each of which may have only a small effect. Nevertheless, study of the mode of action of the FOXP2 gene has helped identify other common genetic variants involved in the same neural pathways that may play a part in causing DLD.

Language disorders are associated with aspects of home environment, and it is often assumed that this is a causal link, with poor language stimulation leading to weak language skills. Twin studies, however, show that two children in the same home environment can have very different language outcomes, suggesting we should consider other explanations for the link. Children with DLD often grow up into adults who have relatively low educational attainments, and their children may share a genetic risk for language disorder.

One non-genetic factor that is known to have a specific impact on language development is being a younger sibling in a large family.

Longitudinal studies indicate that problems are largely resolved by 5 years of age in around 40% of 4-year-olds with early language delays who have no other presenting risk factors. However, for children who still have significant language difficulties at school entry, reading problems are common, even for children who receive specialist help, and educational attainments are typically poor. Poor outcomes are most common in cases where comprehension as well as expressive language is affected. There is also evidence that scores on tests of nonverbal ability of children with DLD decrease over the course of development.

DLD is associated with an elevated risk of social, emotional and mental health concerns. For instance, in a UK survey, 64% of a sample of 11-year-olds with DLD scored above a clinical threshold on a questionnaire for psychiatric difficulties, and 36% were regularly bullied, compared with 12% of comparison children. In the longer-term, studies of adult outcomes of children with DLD have found elevated rates of unemployment, social isolation and psychiatric disorder among those with early comprehension difficulties. However, better outcomes are found for children who have milder difficulties and do not require special educational provision.

Dyscalculia is thought to be present in 3–6% of the general population, but estimates by country and sample vary somewhat. Many studies have found prevalence rates by gender to be equivalent. Those that find gender difference in prevalence rates often find dyscalculia higher in females, but some few studies have found prevalence rates higher in males.

Dyscalculia is difficulty in learning or comprehending arithmetic, such as difficulty in understanding numbers, learning how to manipulate numbers, and learning facts in mathematics. It is generally seen as a specific developmental disorder.

Dyscalculia can occur in people from across the whole IQ range – often higher than average – along with difficulties with time, measurement, and spatial reasoning. Estimates of the prevalence of dyscalculia range between 3 and 6% of the population. In 2004, it was reported that a quarter of children with dyscalculia had ADHD.

In 2015, it was established that 11% of children with dyscalculia also have ADHD. Dyscalculia has also been associated with people who have Turner syndrome and people who have spina bifida.

Mathematical disabilities can occur as the result of some types of brain injury, in which case the proper term, acalculia, is to distinguish it from dyscalculia which is of innate, genetic or developmental origin.

Specific language impairment (SLI) is diagnosed when a child has delayed or disordered language development for no apparent reason. Usually the first indication of SLI is that the child is later than usual in starting to speak and subsequently is delayed in putting words together to form sentences. Spoken language may be immature. In many children with SLI, understanding of language, or "receptive" language, is also impaired, though this may not be obvious unless the child is given a formal assessment.

Although difficulties with use and understanding of complex sentences are a common feature of SLI, the diagnostic criteria encompass a wide range of problems, and for some children other aspects of language are problematic (see below). In general, the term SLI is reserved for children whose language difficulties persist into school age, and so it would not be applied to toddlers who are late to start talking, most of whom catch up with their peer group after a late start.

It is now generally accepted that SLI is a strongly genetic disorder. The best evidence comes from studies of twins. Two twins growing up together are exposed to the same home environment, yet may differ radically in their language skills. Such different outcomes are, however, seen almost exclusively in fraternal (non-identical) twins, who are genetically different. Identical twins share the same genes and tend to be much more similar in language ability.

There can be some variation in the severity and persistence of SLI in identical twins, indicating that environmental factors affect the course of disorder, but it is unusual to find a child with SLI who has an identical twin with normal language.

SLI is not usually caused by a mutation in a single gene. Current evidence suggests that there are many different genes that can influence language learning, and SLI results when a child inherits a particularly detrimental combination of risk factors, each of which may have only a small effect. It has been hypothesized, however, that a mutation of the FOXP2 gene may have an influence on the development on SLI to a certain degree, as it regulates genes pertinent to neural pathways related to language.

Only a handful of non-genetic factors have been found selectively to impact on language development in children. Later-born children in large families are at greater risk than earlier born.

Overall, genetic mutation, hereditary influences, and environmental factors may all have a role in the development and manifestation of SLI. It is important, therefore, to not associate the development to a single factor, but recognize that it is oftentimes the result of complex interactions between any or all of these factors.

In 2006, the U.S. Department of Education indicated that more than 1.4 million students were served in the public schools' special education programs under the speech or language impairment category of IDEA 2004. This estimate does not include children who have speech/language problems secondary to other conditions such as deafness; this means that if all cases of speech or language impairments were included in the estimates, this category of impairment would be the largest. Another source has estimated that communication disorders—a larger category, which also includes hearing disorders—affect one of every 10 people in the United States.

ASHA has cited that 24.1% of children in school in the fall of 2003 received services for speech or language disorders—this amounts to a total of 1,460,583 children between 3 –21 years of age. Again, this estimate does not include children who have speech/language problems secondary to other conditions. Additional ASHA prevalence figures have suggested the following:

- Stuttering affects approximately 4% to 5% of children between the ages of 2 and 4.

- ASHA has indicated that in 2006:

- Almost 69% of SLPs served individuals with fluency problems.

- Almost 29% of SLPs served individuals with voice or resonance disorders.

- Approximately 61% of speech-language pathologists in schools indicated that they served individuals with SLI

- Almost 91% of SLPs in schools indicated that they servedindividuals with phonological/articulation disorder

- Estimates for language difficulty in preschool children range from 2% to 19%.

- Specific Language Impairment (SLI) is extremely common in children, and affects about 7% of the childhood population.

Developmental coordination disorder is a lifelong neurological condition that is more common in males than in females, with a ratio of approximately four males to every female. The exact proportion of people with the disorder is unknown since the disorder can be difficult to detect due to a lack of specific laboratory tests, thus making diagnosis of the condition one of elimination of all other possible causes/diseases. Approximately 5–6% of children are affected by this condition.

Language-based learning disabilities or LBLD are "heterogeneous" neurological differences that can affect skills such as listening, reasoning, speaking, reading, writing, and maths calculations. It is also associated with movement, coordination, and direct attention. LBLD is not usually identified until the child reaches school age. Most people with this disability find it hard to communicate, to express ideas efficiently and what they say may be ambiguous and hard to understand

It is a neurological difference. It is often hereditary, and is frequently associated to specific language problems.

There are two types of learning disabilities: non-verbal, which includes disabilities from psychomotor difficulties to dyscalculia, and verbal, language based.

Dysgraphia is a biologically based disorder with genetic and brain bases. More specifically, it is a working memory problem. In dysgraphia, individuals fail to develop normal connections among different brain regions needed for writing. People with dysgraphia have difficulty in automatically remembering and mastering the sequence of motor movements required to write letters or numbers. Dysgraphia is also in part due to underlying problems in orthographic coding, the orthographic loop, and graphmotor output (the movements that result in writing) by one’s hands, fingers and executive functions involved in letter writing. The orthographic loop is when written words are stored in the mind’s eye, connected through sequential finger movement for motor output through the hand with feedback from the eye.

The causes for learning disabilities are not well understood, and sometimes there is no apparent cause for a learning disability. However, some causes of neurological impairments include:

- Heredity and genetics

- Problems during pregnancy and birth

- Accidents after birth

There are some common problems not related to dysgraphia but often associated with dysgraphia, the most common of which is stress. Often children (and adults) with dysgraphia will become extremely frustrated with the task of writing (and spelling); younger children may cry, pout, or refuse to complete written assignments. This frustration can cause the child (or adult) a great deal of stress and can lead to stress-related illnesses. This can be a result of any symptom of dysgraphia.

It is estimated that up to 16.5% of elementary school aged children present elevated SOR behaviors in the tactile or auditory modalities. However, this figure might represent an underestimation of Sensory Over Responsivity prevalence, since this study did not include children with developmental disorders or those delivered preterm, who are more likely to present it.

This figure is, nonetheless, larger than what previous studies with smaller samples had shown: an estimate of 5–13% of elementary school aged children.

Incidence for the remaining subtypes is currently unknown.

Through the use of compensation strategies, therapy and educational support, dyslexic individuals can learn to read and write. There are techniques and technical aids which help to manage or conceal symptoms of the disorder. Removing stress and anxiety alone can sometimes improve written comprehension. For dyslexia intervention with alphabet-writing systems, the fundamental aim is to increase a child's awareness of correspondences between graphemes (letters) and phonemes (sounds), and to relate these to reading and spelling by teaching how sounds blend into words. It has been found that reinforced collateral training focused on reading and spelling yields longer-lasting gains than oral phonological training alone. Early intervention that is done for children at a young age can be successful in reducing reading failure.

There is some evidence that the use of specially-tailored fonts may help with dyslexia. These fonts, which include Dyslexie, OpenDyslexic, and Lexia Readable, were created based on the idea that many of the letters of the Latin alphabet are visually similar and may, therefore, confuse people with dyslexia. Dyslexie and OpenDyslexic both put emphasis on making each letter more distinctive in order to be more easily identified. The benefits, however, might simply be due to the added spacing between words.

There have been many studies conducted regarding intervention in dyslexia. Among these studies one meta-analysis found that there was functional activation as a result.

There is no evidence demonstrating that the use of music education is effective in improving dyslexic adolescents' reading skills.

A reading disability is a condition in which a sufferer displays difficulty reading resulting primarily from neurological factors. Developmental Dyslexia, Alexia (acquired dyslexia), and Hyperlexia (word-reading ability well above normal for age and IQ).

National Institute of Neurological Disorders and Stroke defines reading disability or dyslexia as follows: "Dyslexia is a brain-based type of learning disability that specifically impairs a person's ability to read. These individuals typically read at levels significantly lower than expected despite having normal intelligence. Although the disorder varies from person to person, common characteristics among people with dyslexia are difficulty with spelling, phonological processing (the manipulation of sounds), and/or rapid visual-verbal responding. In adults, dyslexia usually occurs after a brain injury or in the context of dementia. It can also be inherited in some families, and recent studies have identified a number of genes that may predispose an individual to developing dyslexia."

The NINDS definition is not in keeping with the bulk of scientific studies that conclude that there is no evidence to suggest that dyslexia and intelligence are related. The Rose Review 2009 Definition is more in keeping with modern research and debunked discrepancy model of dyslexia diagnosis:

- Dyslexia is a learning difficulty that primarily affects the skills involved in accurate and fluent word reading and spelling.

- Characteristic features of dyslexia are difficulties in phonological awareness, verbal memory and verbal processing speed.

- Dyslexia occurs across the range of intellectual abilities.

- It is best thought of as a continuum, not a distinct category, and there are no clear cut-off points.

- Co-occurring difficulties may be seen in aspects of language, motor co-ordination, mental calculation, concentration and personal organisation, but these are not, by themselves, markers of dyslexia.

- A good indication of the severity and persistence of dyslexic difficulties can be gained by examining how the individual responds or has responded to well founded intervention.

Deficits in any area of information processing can manifest in a variety of specific learning disabilities. It is possible for an individual to have more than one of these difficulties. This is referred to as comorbidity or co-occurrence of learning disabilities. In the UK, the term "dual diagnosis" is often used to refer to co-occurrence of learning difficulties.

There are many physical health factors associated with developmental disabilities. For some specific syndromes and diagnoses, these are inherent, such as poor heart function in people with Down syndrome. People with severe communication difficulties find it difficult to articulate their health needs, and without adequate support and education might not recognize ill health. Epilepsy, sensory problems (such as poor vision and hearing), obesity and poor dental health are over-represented in this population. Life expectancy among people with developmental disabilities as a group is estimated at 20 years below average, although this is improving with advancements in adaptive and medical technologies, and as people are leading healthier, more fulfilling lives, and some conditions (such as Freeman-Sheldon syndrome) do not impact life expectancy.

It is estimated that 25 to 50% of children diagnosed with Autism Spectrum Disorder (ASD) never develop spoken language beyond a few words or utterances. Despite the growing field of research on ASD, there is not much information available pertaining to individuals with autism who never develop functional language; that, in fact, individuals with nonverbal autism are considered to be underrepresented in all of autism research. Because of the limited research on nonverbal autism, there are not many validated measurements appropriate for this population. For example, while they may be appropriate for younger children, they lack the validity for grade-school aged children and adolescents and have continued to be a roadblock for nonverbal autism research. Often in autism research, individuals with nonverbal autism are sub-grouped with LFA, categorized by learning at most one word or having minimal verbal language.

Most of the existing body of research in nonverbal autism focuses on early interventions that predict successful language outcomes. Research suggests that most spoken language is inherited before the age of five, and the likelihood of acquiring functional language in the future past this age is minimal, that early language development is crucial to educational achievement, employment, independence during adulthood, and social relationships.

DVD/CAS is a motor disorder, which means that the problem is located in the brain and its signals, and not in the mouth. In most cases, the cause is unknown. Possible causes include genetic syndromes and disorders.

Recent research has focused on the significance of the FOXP2 gene in both species and individual development.

Research regarding the KE family, where half the members of the extended family, over three generations, exhibited heritable developmental verbal dyspraxia, were found to have a defective copy of the FOXP2 gene. and further studies suggest that the FOXP2 gene as well as other genetic issues could explain DVD/CAS. including 16p11.2 microdeletion syndrome.

Birth/prenatal injuries, as well as stroke, can also be causes of DVD/CAS. Furthermore, DVD/CAS can occur as a secondary characteristic to a variety of other conditions. These include autism, some forms of epilepsy, fragile X syndrome, galactosemia, and chromosome translocations involving duplications or deletions.

Mixed receptive-expressive language disorder (DSM-IV 315.32) is a communication disorder in which both the receptive and expressive areas of communication may be affected in any degree, from mild to severe. Children with this disorder have difficulty understanding words and sentences. This impairment is classified by deficiencies in expressive and receptive language development that is not attributed to sensory deficits, nonverbal intellectual deficits, a neurological condition, environmental deprivation or psychiatric impairments. Research illustrates that 2% to 4% of 5 year olds have mixed receptive-expressive language disorder. This distinction is made when children have issues in expressive language skills, the production of language, and when children also have issues in receptive language skills, the understanding of language. Those with mixed receptive-language disorder have a normal left-right anatomical asymmetry of the planum temporale and parietale. This is attributed to a reduced left hemisphere functional specialization for language. Taken from a measure of cerebral blood flow (SPECT) in phonemic discrimination tasks, children with mixed receptive-expressive language disorder do not exhibit the expected predominant left hemisphere activation. Mixed receptive-expressive language disorder is also known as receptive-expressive language impairment (RELI) or receptive language disorder.

LBLD can be an enduring problem. Some people might experience overlapping learning disabilities that make improvement problematic. Others with single disabilities often show more improvement. Most subjects can achieve literacy via coping mechanisms and education.

Nonverbal learning disorder (also known as nonverbal learning disability, NLD, or NVLD) is a learning disorder characterized by verbal strengths as well as visual-spatial, motor, and social skills difficulties. It is sometimes confused with Asperger Syndrome or high IQ. Nonverbal learning disorder has never been included in the American Psychiatric Association's "Diagnostic and Statistical Manual of Mental Disorders" or the World Health Organization's "International Classification of Diseases".

Hyperlexia is a syndrome characterized by a child's precocious ability to read. It was initially identified by Norman E. Silberberg and Margaret C. Silberberg (1967), who defined it as the precocious ability to read words without prior training in learning to read, typically before the age of 5. They indicated that children with hyperlexia have a significantly higher word-decoding ability than their reading comprehension levels. Children with hyperlexia also present with an intense fascination for written material at a very early age.

Hyperlexic children are characterized by having average or above-average IQs, and word-reading ability well above what would be expected given their age. First named and scientifically described in 1967 (Silverberg and Silverberg), it can be viewed as a superability in which word recognition ability goes far above expected levels of skill. Some hyperlexics, however, have trouble understanding speech. Some experts believe that most, or perhaps all children with hyperlexia, lie on the autism spectrum. However, one expert, Darold Treffert, proposes that hyperlexia has subtypes, only some of which overlap with autism. Between 5 and 20 percent of autistic children have been estimated to be hyperlexic.

Hyperlexic children are often fascinated by letters or numbers. They are extremely good at decoding language and thus often become very early readers. Some hyperlexic children learn to spell long words (such as "elephant") before they are two years old and learn to read whole sentences before they turn three.

An fMRI study of a single child showed that hyperlexia may be the neurological opposite of dyslexia.