Down syndrome is a genetic abnormality characterised by trisomy 21 (95%), with the remaining 5% being due to translocations. It occurs in 1 per 600-800 births in Australia.
The diagnosis of Down syndrome is often made by antenatal screening. When this has not occurred, it can usually be diagnosed based on the typical phenotypic features present in the newborn including:
- up-slanting palpebral fissures
- epicanthic folds
- flat facial profile
- low-set small ears
- open mouth with protruding tongue
- short neck with increased nape skin
- short broad hands with incurved 5th finger (clinodactyly) & transverse palmar crease
- space between first and second toes
- hypotonia
Rapid confirmation of the diagnosis is possible with a FISH for trisomy 21 followed by a full karyotype to detect Down syndrome due to translocations.
- Diagnosis of Down syndrome is generally made by either antenatal screening or genetic testing in a newborn with typical dysmorphic features.
- The medical management of a child with Down syndrome is centred around surveillance for common associated health issues and anticipatory guidance for families - see RCH General Medicine, Screening for Children with Down Syndrome.
Medical management is centred around surveillance for common health issues and anticipatory guidance for families - see RCH General Medicine, Screening for Children with Down Syndrome.
There are many associations with Down syndrome which need to be considered, including:
- intellectual deficits and developmental delay
- cardiac abnormalities (50%)
- gastrointestinal complications (incl. celiac disease)
- growth issues (including obesity) - see Down syndrome growth charts
- eye abnormalities
- hearing deficits and effusions
- endocrine problems (esp. diabetes, hypothyroidism)
- behavioural difficulties
- haematological abnormalities
- immune defects
- sleep apnoea
- atlanto-axial instability
- fertility problems
- Paediatrician
- Early referral to paediatric outpatient services is recommended for all children with Down syndrome.
- Support Services
- Early Childhood Intervention Services are recommended for any child with Down syndrome who exhibits more than a single area of developmental delay. In the unusual circumstance of only a single area of delay, individual allied health referral can be undertaken.
- Children with a diagnosis of Down syndrome are automatically eligible for funding under the Better Start for Children with Disabilities package.
- Down Syndrome Victoria provides a range of information and support services for people with Down syndrome and their families.
- Disability Services provides government funded specialist disability supports for people with disabilities and their families.
- Other resources
- Down syndrome growth charts
- Down syndrome growth charts