Overview of syndromes and disorders associated with developmental disability

There is an increasing number of identified rare aetiologies associated with developmental disability that a general practitioner (GP) may need to manage. In addition to specialist multidisciplinary input, the GP has an important role in the care of the person, providing regular health surveillance and support; see Role of the general practitioner in the care of a person with developmental disability.

For advice on assessment of a person with developmental delay or disability, see here.

Once an aetiology for a developmental disability has been established, it can be useful to include a summary of the specific risk factors associated with the aetiology as a reminder in the patient health record. These factors should be reviewed as clinically indicated and as part of the person’s annual comprehensive health assessment. Many aetiologies for rare developmental disabilities will have established behaviour phenotypes, which are important determinants for management and support of patients. People with developmental disability and their family or carers may have researched the condition and can often contribute to clinical information. Information specific to the aetiology can be helpful to include when drawing up a National Disability Insurance Scheme (NDIS) support plan.

Syndromes and disorders associated with developmental disability includes links to information about a selection of common and rare causes of developmental disability, including management considerations and links to Australian and international support organisations.

Resources for information about syndromes and disorders associated with developmental disability links to resources that provide valuable evidence-based information for both clinicians and families on the syndromes and disorders associated with developmental disability.

Figure 1. Resources for information about syndromes and disorders associated with developmental disability.

[NB1]

Better Health Channel Genetic conditions, State Government of Victoria

GeneReviews, National Center for Biotechnology Information (NCBI) (US)

Genomics in general practice , Royal Australian College of General Practitioners (RACGP)

Mayo Clinic (US), diseases and conditions

MedlinePlus Genetics US National Library of Medicine

National Center for Advancing Translational Sciences, Genetic and Rare Diseases Information Center (GARD) (US)

National Organization for Rare Disorders (NORD) (US)

Online Mendelian Inheritance in Man (OMIM) (US), a catalogue of human genes and genetic disorders

Rare Voices Australia

Society for the Study of Behavioural Phenotypes: syndrome sheets

Unique Understanding rare chromosome and gene disorder guides

Note: NB1: This is not an exhaustive list.

Recommended practice during a consultation with a person with developmental disability is outlined in General practice and emergency presentation of a person with developmental disability.

For advice on the general health care of people with developmental disability at various life stages, see children, adolescents, adults or people who are ageing.

Table 1. Syndromes and disorders associated with developmental disability
[NB1] [NB2]
22q11.2 deletion syndrome Angelman syndrome Autism spectrum disorder Cerebral palsy CHARGE syndrome Coffin–Lowry syndrome Cornelia de Lange syndrome Cri du chat syndrome Down syndrome Fetal alcohol spectrum disorder Fragile X syndrome Lesch Nyhan syndrome Neurofibromatosis type 1 Noonan syndrome Phelan–McDermid syndrome (22q13.3 deletion syndrome) Prader–Willi syndrome Rett syndrome Smith–Magenis syndrome Sotos syndrome Tuberous sclerosis complex Williams syndrome
22q11.2 deletion syndrome
frequency	estimated prevalence 1 in 4000
genetic cause	introduction to 22q11.2 deletion syndrome
characteristics	clinical characteristics of 22q11.2 deletion syndrome
health considerations	preventive health and screening for people with 22q11.2 deletion syndrome
support organisations	22q Foundation Australia and New Zealand
Angelman syndrome
frequency	estimated 1 in 12 000 to 20 000 people
genetic cause	MedlinePlus
characteristics	MedlinePlus
health considerations	GeneReviews
support organisations	Angelman Syndrome Association (ASA) Australia
Autism spectrum disorder
frequency	around 1% of the population; estimated 1 in 70 to 150 people
genetic cause	MedlinePlus
characteristics	clinical characteristics of autism spectrum disorder
health considerations	preventive health and screening for people with autism spectrum disorder
support organisations	Aspect (autism spectrum Australia)
Cerebral palsy
frequency	about 35 500 people in Australia; 1.4 in 1000 live births in Australia
genetic cause	not applicable; causes of cerebral palsy
characteristics	clinical characteristics of cerebral palsy
health considerations	preventive health and screening for people with cerebral palsy
support organisations	Cerebral Palsy Australia; State-based support organisations are listed in Resources for information about syndromes and disorders associated with developmental disability
CHARGE syndrome
frequency	approximately 1 in 8500 to 10 000 newborns
genetic cause	MedlinePlus
characteristics	MedlinePlus
health considerations	GeneReviews
support organisations	CHARGE Syndrome Association of Australasia; The CHARGE Syndrome Foundation (US)
Coffin–Lowry syndrome
frequency	estimated 1 in 40 000 to 50 000 people
genetic cause	MedlinePlus
characteristics	MedlinePlus
health considerations	GeneReviews
support organisations	Coffin–Lowry Syndrome Foundation (US)
Cornelia de Lange syndrome
frequency	exact incidence unknown; likely 1 in 10 000 to 30 000 newborns
genetic cause	MedlinePlus
characteristics	MedlinePlus
health considerations	GeneReviews
support organisations	Cornelia de Lange Syndrome (CdLS) Association (Australasia) Inc
Cri du chat syndrome
frequency	estimated 1 in 20 000 to 50 000 newborns
genetic cause	MedlinePlus
characteristics	MedlinePlus
health considerations	StatPearls
support organisations	Cri du Chat Support Group of Australia Inc
Down syndrome
frequency	approximately 1 in 800 newborns
genetic cause	cause of Down syndrome
characteristics	clinical characteristics of Down syndrome
health considerations	preventive health and screening for people with Down syndrome
support organisations	Down Syndrome Australia, includes links to state-based support organisations
Fetal alcohol spectrum disorder
frequency	no reliable national prevalence data for the general Australian population
genetic cause	not applicable
characteristics	clinical characteristics of fetal alcohol spectrum disorder
health considerations	preventive health and screening for people with fetal alcohol spectrum disorder
support organisations	National Organisation for Fetal Alcohol Spectrum Disorder (NOFASD) Australia
Fragile X syndrome
frequency	approximately 1 in 3600 to 4000 people in the general population
genetic cause	cause of fragile X syndrome
characteristics	clinical characteristics of fragile X syndrome
health considerations	preventive health and screening for people with fragile X syndrome
support organisations	Fragile X Alliance Inc; The Fragile X Association of Australia; National Fragile X Foundation (US)
Lesch Nyhan syndrome
frequency	approximately 1 in 380 000 individuals
genetic cause	MedlinePlus
characteristics	MedlinePlus
health considerations	GeneReviews
support organisations	included in Genetic Alliance Australia
Neurofibromatosis type 1
frequency	estimated 1 in 3000 people
genetic cause	introduction to neurofibromatosis type 1
characteristics	clinical characteristics of neurofibromatosis type 1
health considerations	preventive health and screening for people with neurofibromatosis type 1
support organisations	Children’s Tumour Foundation; Children’s Tumor Foundation (US)
Noonan syndrome
frequency	approximately 1 in 1000 to 2500 people
genetic cause	MedlinePlus
characteristics	MedlinePlus
health considerations	GeneReviews
support organisations	Noonan Syndrome Awareness Association (NSAA)
Phelan–McDermid syndrome (22q13.3 deletion syndrome)
frequency	more than 2200 people diagnosed worldwide
genetic cause	MedlinePlus
characteristics	MedlinePlus
health considerations	GeneReviews
support organisations	Phelan–McDermid Syndrome Foundation (PMSF) Australia Phelan–McDermid Syndrome Foundation (PMSF) (US)
Prader–Willi syndrome
frequency	estimated 1 in 10 000 to 30 000 people
genetic cause	MedlinePlus
characteristics	MedlinePlus
health considerations	GeneReviews
support organisations	Prader–Willi Syndrome Australia (PWSA)
Rett syndrome
frequency	estimated 1 in 9000 to 10 000 females
genetic cause	MedlinePlus
characteristics	MedlinePlus
health considerations	GeneReviews
support organisations	Rett Syndrome Association of Australia
Smith–Magenis syndrome
frequency	at least 1 in 25 000 individuals; possibly 1 in 15 000 individuals
genetic cause	MedlinePlus
characteristics	MedlinePlus
health considerations	GeneReviews
support organisations	Smith–Magenis Syndrome Australia
Sotos syndrome
frequency	reported to occur in 1 in 10 000 to 14 000 newborns
genetic cause	MedlinePlus
characteristics	MedlinePlus
health considerations	GeneReviews
support organisations	Sotos Syndrome Australasia
Tuberous sclerosis complex
frequency	about 1 in 6000 people
genetic cause	MedlinePlus
characteristics	MedlinePlus
health considerations	GeneReviews
support organisations	Tuberous Sclerosis Australia (TSC)
Williams syndrome
frequency	estimated 1 in 7500 to 10 000 people
genetic cause	MedlinePlus
characteristics	MedlinePlus
health considerations	GeneReviews
support organisations	Williams Syndrome Australia; Williams Syndrome Foundation (UK)
Note: NB1: As well as links to information in these guidelines, links are provided to information in MedlinePlus (National Institutes of Health [NIH], US National Library of Medicine), and in GeneReviews and StatPearls (National Center for Biotechnology Information [NCBI], US National Library of Medicine). NB2: Resources for information about syndromes and disorders associated with developmental disability lists some other sources of information about syndromes and disorders associated with developmental disability.