Global developmental delay is an umbrella term used when children are significantly delayed in their
cognitive and
physical development. It can be diagnosed when a child is delayed in one or more milestones, categorised into
motor skill
A motor skill is a function that involves specific movements of the body's muscles to perform a certain task. These tasks could include walking, running, or riding a bike. In order to perform this skill, the body's nervous system, muscles, and br ...
s,
speech, cognitive skills, and social and emotional development. There is usually a specific condition which causes this delay, such as
Fragile X syndrome or other
chromosomal abnormalities. However, it is sometimes difficult to identify this underlying condition.
Other terms associated with this condition are
failure to thrive
Failure to thrive (FTT), also known as weight faltering or faltering growth, indicates insufficient weight gain or absence of appropriate physical growth in children. FTT is usually defined in terms of weight, and can be evaluated either by a low ...
(which focuses on lack of weight gain and physical development),
intellectual disability
Intellectual disability (ID), also known as general learning disability in the United Kingdom and formerly mental retardation, Rosa's Law, Pub. L. 111-256124 Stat. 2643(2010). is a generalized neurodevelopmental disorder characterized by signif ...
(which focuses on intellectual deficits and the changes they cause to development) and
developmental disability
Developmental disability is a diverse group of chronic conditions, comprising mental or physical impairments that arise before adulthood. Developmental disabilities cause individuals living with them many difficulties in certain areas of life, espe ...
(which can refer to both intellectual and physical disability altering development).
Causes
Developmental delay can be caused by
learning disabilities
Learning disability, learning disorder, or learning difficulty (British English) is a condition in the brain that causes difficulties comprehending or processing information and can be caused by several different factors. Given the "difficult ...
, in which case the delay can usually be overcome with time and support - such as with physiotherapists, occupational therapists, vision therapists, and speech and language therapists.
Other causes which may cause a permanent delay in development include genetic disorders such as
Down syndrome
Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is usually associated with physical growth delays, mild to moderate intellectual dis ...
and
Fragile X, childhood infections such as
meningitis or
encephalitis, and metabolic disorders such as
hypothyroidism. Metabolic disorders are more likely to cause delayed development in older children, as many congenital metabolic problems which are easily managed are
screened for in the neonatal period. Child born prematurely (born before 37 weeks). The use of toxic substances in pregnancy, particularly alcohol, can lead to developmental delay if they affect the neurological development of the fetus, such as in
fetal alcohol syndrome. Even though there are many known causes of delay, some children will never receive a diagnosis.
Investigation
Developmental monitoring is performed during wellness visits to check a child's development.
Health authorities encourage parents to monitor their child's development, the
CDC's program "Learn the Signs. Act Early" provides materials for a child's development is assessed based on expected milestones for actions like how they play, learn, speak, act and move. Missed milestones may be cause for concern, so the doctor or another specialist may call for a more thorough test or exam to take a closer look, this is usually done by going through Developmental Screening.
Developmental Screening is a more involved process. The evaluating professional will ask a parent to complete a research-based questionnaire that asks about a child's development, including language, movement, thinking, behavior, and emotions. Developmental Screening is recommended by the
American Academy of Pediatrics (AAP) to all children at 9, 18, and 30 months. The AAP also recommends that all children be screened specifically for
autism spectrum disorder
The autism spectrum, often referred to as just autism or in the context of a professional diagnosis autism spectrum disorder (ASD) or autism spectrum condition (ASC), is a neurodevelopmental condition (or conditions) characterized by difficulti ...
(ASD) during regular well-child visits at 18 and 24 months.
If a Developmental Screening indicates a delay, the child should then be assessed with a Developmental Evaluation.
Developmental Evaluations are performed by a Developmental pediatrician, child psychologist, or other trained provider with the purpose of Identifying and diagnosing developmental delays and conditions.
*
Chromosome microarray and karyotyping to look for trisomy, microdeletions, and duplications. It is the most sensitive diagnostic test available and is used first line in all cases, but can miss balanced translocations and low-level
mosaicism
Mosaicism or genetic mosaicism is a condition in multicellular organisms in which a single organism possesses more than one genetic line as the result of genetic mutation. This means that various genetic lines resulted from a single fertilized ...
.
* Specific gene testing is available for certain disorders such as
Rett syndrome
Rett syndrome (RTT) is a genetic disorder that typically becomes apparent after 6–18 months of age and almost exclusively in females. Symptoms include impairments in language and coordination, and repetitive movements. Those affected often h ...
, although these are expensive tests which aren't widely available
* Selective metabolic investigations may be useful in the absence of other identifiable causes, and the specific tests done will depend on the presentation. Inborn errors of metabolism causing metabolic disorders are rare and there are limited treatment options even if they are successfully diagnosed.
* Targeted
MRI brain can be considered second line in selected patients, and is more likely to contribute to a diagnosis if the child has abnormal physical signs such as
microcephaly
Microcephaly (from New Latin ''microcephalia'', from Ancient Greek μικρός ''mikrós'' "small" and κεφαλή ''kephalé'' "head") is a medical condition involving a smaller-than-normal head. Microcephaly may be present at birth or it ...
,
macrocephaly
Macrocephaly is a condition in which circumference of the human head is abnormally large. It may be pathological or harmless, and can be a familial genetic characteristic. People diagnosed with macrocephaly will receive further medical tests to ...
, a change in head circumference, focal neurological signs, or
epilepsy
Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrica ...
.
Neonatal screening is used in the UK (
Guthrie test) and can diagnose certain inborn errors of metabolism before they cause significant developmental problems, with the aim to manage them so that no permanent damage occurs.
*
Medium-chain acyl-CoA dehydrogenase deficiency
Medium-chain acyl-CoA dehydrogenase deficiency (MCAD deficiency or MCADD) is a disorder of fatty acid oxidation that impairs the body's ability to break down medium-chain fatty acids into acetyl-CoA. The disorder is characterized by hypoglycemia ...
*
Homocystinuria
Homocystinuria or HCU is an inherited disorder of the metabolism of the amino acid methionine due to a deficiency of cystathionine beta synthase or methionine synthase. It is an inherited autosomal recessive trait, which means a child needs to i ...
*
Congenital hypothyroidism
Congenital hypothyroidism (CH) is thyroid hormone deficiency present at birth. If untreated for several months after birth, severe congenital hypothyroidism can lead to growth failure and permanent intellectual disability. Infants born with con ...
*
Isovaleric acidemia
*
Glutaricaciduria type 1
*
Maple syrup urine disease
Canada, the US, and the Netherlands offer more extensive newborn screening, encompassing some other amino acid, organic, and urea cycle disorders.
Management
The specific management of children with global developmental delay will depend on their individual needs and underlying diagnosis. Early intervention is essential to support the child to reach their full potential. Specialists involved in the management of GDD in children include:
* Speech therapists
* Physical therapists
* Vision therapist
* Occupational therapists
* Music therapists
* Hearing specialists (Audiologist)
* Developmental paediatricians
* Neurologists
* Providers of Early Intervention Services (depending on location)
As well as involving professionals, parents can support the development of their child by playing with them, reading with them, showing them how to do tasks, and supporting them to participate in activities of daily living such as washing, dressing, and eating.
See also
*
Specific developmental disorder
References
{{Reflist
Child development
Developmental disabilities