The term “Global Developmental Delay” is used when a child is both cognitively and physically behind other children their age. A child may have a developmental delay when he or she is behind in one or more parts of development, such as motor skills, speech, cognitive abilities, or social and emotional development. When this happens, there will usually be a specific condition present such as Fragile X syndrome or another form of chromosomal abnormality. Unfortunately, this can be very difficult to diagnose.
In addition to failure to thrive, other terms linked to this condition include intellectual disability, developmental disability, and failure to thrive (which is focused on both failure to thrive and failure to thrive).
Read: Developmental Coordination Disorder
Difference between global developmental delay and autism spectrum disorder
GDD presents fewer learning barriers than autism spectrum disorder, even though there are many similarities in behaviour and development. A study found that children with GDD had better imitation skills than children with ASD, a key early learning skill.
When interacting with others, children diagnosed with GDD typically respond more appropriately than children without GDD. It has been shown that children with GDD present with a greater delay in their ability to solve problems, develop motor skills, and engage in adaptive behaviors compared to their peers with autism spectrum disorder.
Studies have shown that as the child gets older, it becomes easier to identify the differences between GDD and ASD.
Children with ASD typically present with:
- Repeated behaviors (e.g., flapping hands, rocking back and forth without communicating)
- Having difficulty interacting with others socially
- Imitation of other people’s actions, sounds, or words is limited
- Fixations on one topic or toy or fixations on nonfunctional objects in their environment
Global developmental delay causes
A child’s development may be delayed by learning disabilities; in such cases, support can usually be provided by physiotherapists, occupational therapists, and speech therapists to help them meet their developmental goals. As well as genetic disorders, children can suffer from infections such as meningitis and encephalitis as well as metabolic conditions like hypothyroidism, which may cause a permanent delay in their development.
Since congenital metabolic problems are often screened for in the neonatal period, it is more likely that older children will experience developmental delays due to metabolic disorders. Alcohol is a toxic substance, especially during pregnancy, which can affect the fetus’ neurological development and cause developmental delay, such as fetal alcohol syndrome. Many children will not receive a diagnosis of a delay, despite many known causes.
Global developmental delay symptoms
Global developmental delay affects children differently and can present in a variety of ways. Children who have GDD may experience delays in many areas of development. They may experience delays in:
- Speech and language development
- Gross motor development (walking, crawling)
- Fine motor development (holding toys, drawing)
- Thinking, understanding and learning
- Making friends and interacting with others
- Emotional regulation
- Daily living activities (getting dressed, using the restroom)
Children and their families can function in different ways depending on the combination and degree of delays in their development. In order to come to a diagnosis, children may undergo a range of assessments, such as:
- Vision and Hearing tests
- Speech and language assessment
- Behaviour tests
- Cognitive assessment
- Activities of daily living assessment
- Blood tests
- Genetic and chromosomal tests
- Neurological test
Read: Intellectual Development Disorder
Global developmental delay diagnoses
Checking a child’s development during wellness visits is part of developmental monitoring. A program called “Learn the Signs. Act Early” is designed to help parents monitor their children’s development, with materials that measure how children play, learn, speak and act. Doctors or other specialists may need to take a closer look at a child who has missed milestones; this is typically done by doing a Developmental Screening.
Developmental Screening can be an intensive process. A survey asking about a child’s development will be given to the parent by an evaluating professional. The survey will cover language, movement, thinking, behavior and emotions. AAP recommends that all children under the age of 9 undergo developmental screenings at 18 and 30 months.
All children should also have their development monitored specifically for autism spectrum disorders (ASD) at their 18-month and 24-month well-child visits, according to the AAP. A developmental evaluation should be conducted if the child’s Screening indicates a delay.
The purpose of developmental evaluations is to identify and diagnose developmental delays and conditions. These evaluations can be conducted by a developmental pediatrician, child psychologist, or other trained professional.
- An array of chromosomes and karyotyping are performed to determine whether there are trisomies, microdeletions and duplications. The test is the most accurate and is used in all cases as the first step of diagnosis, but it misses balanced translocations as well as low-level mosaicisms.
- Some disorders, such as Rett syndrome, can be tested for specific genes, but these tests are expensive and aren’t widely available.
- If no other underlying cause is evident, selective metabolic investigations are useful, with specific tests performed based on the presentation. Metabolic disorders caused by inborn errors of metabolism are rare, and even if they are diagnosed, they have limited treatment options.
- It’s a good idea to do a targeted MRI brain scan in selected patients, especially those with abnormal physical signs such as macrocephaly, microcephaly, a change in head circumference, neurological symptoms, or epilepsy.
In the UK, there is a screening program to diagnose certain inborn metabolic disorders at the time of birth (Guthrie test). The goal is to manage these disorders so that permanent damage to the fetus is avoided.
- Medium-chain acyl-CoA dehydrogenase deficiency
- Congenital hypothyroidism
- Isovaleric acidaemia
- Glutaricaciduria type 1
- Maple syrup urine disease
Some other amino acid, organic, and urea cycle disorders can be covered by newborn screening in Canada, the United States, and the Netherlands.
Read: Pervasive Developmental Disorder
Managing the development delay
Individual management plans will depend on the child’s underlying diagnosis and his or her specific needs. The key to supporting the child is to provide early intervention. Child specialists who work with GDD include
- Speech therapists
- Physical therapists
- Occupational therapists
- Hearing specialists (Audiologist)
- Developmental paediatricians
- Service providers for early intervention services (based on location)
Parenting is not just about professionals – parents can help their kids grow by playing with them, reading to them, teaching them how to do things, and helping them with things like washing up, dressing, eating, and going to the bathroom.