Downs syndrome

Question 1

What is downs syndrome?

Answer 1

It is a congenital condition (present from birth)

Question 2

What is the risk of downs syndrome ?

Answer 2

1 in 1000 babies are affected (risk increases with maternal age)

Question 3

What is the primary genetic mutation causing downs syndrome ?

Answer 3

Trisomy 21

Question 4

What are the 3 different subtypes of downs syndrome ?

Answer 4

1. Non-dysjunction (trisomy 21) - there is an extra copy of chromosome 21 in every cell - 94% of cases
2. Robertsonian translocation - the total no. of chromosomes stays the same (46) but an additional full or partial copy of chromosome 21 attaches to another chromosome usually 14
3. Mosaicism - there is an extra chromosome 21 in some but not all of their cells, may have few DS characteristics

Question 5

What are the characteristic features of downs syndrome ?

Answer 5

• face: upslanting palpebral fissures, epicanthic folds, Brushfield spots in iris, protruding tongue, small low-set ears, round/flat face, small nose and flat nasal bridge
• flat occiput
• short neck
• single palmar crease (simian crease), pronounced ‘sandal gap’ between big and first toe
• Broad hands with short fingers
• hypotonia
• Below average birth weight & length

Question 6

All children with DS have some degree of learning disability & delayed development - T or F?

Answer 6

True - but the degree of which varies widely

Question 7

Around 1 in 10 DS patients have others developmental conditions such as…

Answer 7

ADHD and Autism spectrum disorder (ASD)

Question 8

What are the health problems/complications associated with DS?

Answer 8

• Cervical spine instability
• Heart defects: 1 in 2 are born with a congenital heart defect. The most common are septal defects (e.g. atrioventricular septal canal defect)
• Gut problems: coeilacs disease, small bowel obstruction, reflux, hirsprungs disease, dudoenal atresia
• Hearing problems: due to narrow ear canals
• Vision problems: often need glasses
• Thyroid problems: most commonly hypothyroidism
• Infections: more likely due to poorly developed immune system
• Dementia: Alzhiemers especially (risk of it developing at a younger age)
• ALL risk
• Subfertility