[MND] Downs Syndrome

Question 1

Definition

Answer 1

A genetic syndrome relating to an abnormality associated with chromosome 21. The syndrome comprises of several physical and psychological features and an increased risk of medical complications

Question 2

Cause

Answer 2

In 95% of cases it is because there is an extra copy of chromosome 21 occurring in the developing foetus resulting in the child being born with 47 chromosomes in each cell instead of 46. This changes the normal development of the body and brain

Question 3

Risk Factors

Answer 3

• Increased risk with increasing age of mother

- Previous birth of a baby with Downs Syndrome

Question 4

Epidemiology

Answer 4

• Most common genetic disorder causing intellectual disability
• Occurs in approx. 1 in 1000 live births
• Incidence increases with mothers age. (1 in 25 @ 45 years of age)

Question 5

Pathophysiology

Answer 5

• Each cell in the body normally has 46 chromosomes in each cell. Each chromosome is organised into hundreds of genes
• Abnormal cell division during the formation of an egg or sperm results in an additional copy of chromosome 21
• Results in malformations and developmental abnormalities. Many foetuses spontaneously abort

Question 6

Common Physical Clinical Features

Answer 6

• Facial (small ears, white spots in iris of eyes)
• Short neck
• Low muscle tone, loose ligaments
• Small hands and feet
• Short stature

Question 7

There is delayed motor development and varying levels of intellectual disability which include:

Answer 7

• Delay in motor milestones (i.e. sitting, standing, walking, and fine motor skills)
• Delay in acquiring spoken language but socially responsive
• Mild to moderate cognitive impairment. - - Autism / attention deficits, cognitive impairments, more obvious in older childhood as intellectual disability develops more slowly than normal

Question 8

Associated health conditions may include:

Answer 8

Congenital heart defects, hearing loss, eye problems, gastrointestinal problems, thyroid dysfunction, low resting metabolic rate (incr risk of weight gain), musculoskeletal problems associated with hypotonia

Question 9

Diagnosis

Answer 9

Before Birth:
Screening through blood tests and ultrasound tests

After Birth:
Clinical observations combined with blood tests to confirm DS

Question 10

Interdisciplinary Management

Answer 10

• Routine monitoring of possible medical conditions starting in infancy e.g. eye and hearing, heart disease, diabetes, hypothyroidism
• Monitoring and treatment of mental health disorders such as depression in later life
• Surgery for heart defects
• Information and support for parents along with genetic counselling

Question 11

Prognosis

Answer 11

• Currently average life expectancy is mid-fifties. Prognosis is affected by effective management of medical conditions associated with DS
• Since 1970s prognosis for a productive and positive life has improved with more educational opportunities and supported employment