PBL 6: Developmental Delay and Disability Flashcards
(31 cards)
What is Down syndrome?
A genetic disorder due to a partial or full 3rd copy of chromosome 21.
Define portage staff
Portage is a home visiting educational service for children aged 2-4 with additional support needs and their families.
What are glue ears?
Otitis media with effusion; middle ear becomes filled with fluid.
What is a non-disjunction trisomy?
- In non-disjunction meiosis, a gamete is formed with an extra copy of chromosome 21, giving it 24 chromosomes over all.
- There is failure of the sister chromatids to separate properly during cell division.
- When combined with a typical gamete from the other parent, the foetus will have 47 chromosomes.
What will it present as? (non-disjunction trisomy)
47XY+21
Does meiotic dysjunction typically occur in mother or father?
Mother
What happens if mitotic non junction occurs?
Mosaic pattern as some cells will have trisomy 21 and some not
What is the type of translation called that can cause down syndrome?
Robertsonian
What is robertsonian translocation?
long arm (q) of chromosome 21 attaches to the long arm of chromosome 14. Happens on acromatic chromosomes (which there are 5)
What is the karyotype of a male with down syndrome?
46XYt(14;21)
Where does translational Down syndrome occur usually?
Mother who have a balanced translocation
Genetic chance for down syndrome for a translocation carrier having a child?
1/3
S+S of down syndrome?
• Physical abnormalities: - Slanted eyes. - Muscle tone. - Large tongue. - Short stature. • Mental impairment. • Irregular and slurred speech. • Epileptic seizures.
What do you see in an ultrasound?
nuchal translucency detects the fluid collection in the neck
What do you look for in blood when screening?
raised pregnancy associated plasma protein A (PAPP-A) and Alpha-fetoprotein levels.
How to diagnose down syndrome specifically?
- Chorionic villous sampling is a prenatal test used to determine genetic disorders in the foetus.
- Amniocentesis
What congenital heart defects?
- 60% babies with DS are born with congenital heart defects.
- AV septal defect is most common.
- Atrial septal defect.
- Ventricular septal defect.
- Tetralogy of Fallot.
- Transposition of great arteries.
What complications can you get with the GI tract?
- Bowel atresia; most commonly in the duodenum.
- GORD.
- Hirschsprung’s disease (colonic dilation).
- Coeliac disease.
What complications can you get with endocrine?
- Hypothyroidism.
- T1DM.
- Obesity.
- Short stature.
What complications can you get with eyes?
- Neonatal cataracts.
- Nystagmus.
- Refractive errors.
What complications can you get with bones?
• Atlanto-occipital (Atlasoccipital bone) instability.
How can alzheimers disease be affected by down syndrome?
- 50% DS have dementia >50 years old.
- APP gene is also found on chromosome 21, so is linked to Down syndrome.
- All DS patients >35 have Beta plaques and neurofibrillary tangles.
How is cancer affected by down syndrome?
- Increased risk of acute lymphoblastic leukaemia.
- Testicular cancer.
- Tumour suppressor genes are thought to be found on chromosome 21.
How is choronic secretory otitis media affected by down syndrome?
- Due to persistence of sticky mucous in the middle ear.
- Causes deafness.
- Management is usually waiting and watching.
- Hearing aids may be fitted.
