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Flashcards in Paeds Genetics Deck (39)
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1
Q

what is trisomy 21 also known as

A

Down’s syndrome

2
Q

what are the dysmorphic features of Down’s syndrome

A

brachycephaly (small head and flat back)

hypotonia (reduced muscle tone)

short neck

short stature

flattened face and nose

prominent epicanthic folds (folds of skin overlying medial portion of eye and eyelid)

upward sloping palpebral fissures (gaps between lower and upper eyelid)

single palmar crease

3
Q

what are some complications of Down’s syndrome

A

learning disability

recurrent otitis media

deafness (due to recurrent glue ear and conductive hearing loss)

visual problems

hypothyroidism

cardiac defects (ASD, VSD, PDA and TOF)

atlantoaxial instability

leukaemia (especially AML)

dementia

4
Q

what is the 1st line screening for Down’s syndrome

A

Combined test (most accurate test)

US measures nuchal translucency + maternal blood tests

5
Q

result of combined test screening that suggests Down’s syndrome

A

Nuchal thickness >6mm

high beta-HCG levels

low pregnancy-associated plasma protein A (PAPPA)

6
Q

when is 1st line screening for Down’s syndrome done

A

between 11 and 14 weeks

7
Q

what is the triple test for Down’s syndrome

A

maternal bloods:

beta-HCG
alphafetoprotein
serum oestriol

8
Q

when is the triple test screen done and what does it show for Down’s

A

14-20 weeks

high beta-HCG
low AFP
low oestriol

9
Q

if screening shows increases risk, what testing is offered for Down’s

A

amniocentesis (done later in pregnancy)

chronic villus sampling (if earlier than 15 weeks)

10
Q

what routine investigations are done for children with Down’s syndrome

A

Regular thyroid check (2 yearly)

echocardiogram to look for cardiac defects

regular audiometry for hearing impairment

regular eye checks

11
Q

life expectancy for Down’s syndrome

A

60 years

12
Q

what is Kleinfelter Syndrome

A

male has additional X chromosome

47XXY

13
Q

features of Kleinfelter’s syndrome

A

features develop at puberty

taller height 
wider hips
gynaecomastia
weaker muscles
small testicles
reduced libido 
shyness
infertility 
subtle learning difficulties
14
Q

how is Kleinfelter’s managed

A

testosterone injections
IVF techniques
breast reduction surgery

15
Q

what is Turner syndrome

A

Female has a single X chromosome

45 XO

16
Q

features of Turner syndrome

A

short stature

webbed neck

high arching palate

downward sloping eyes with ptosis

broad chest with widely spaced nipples

cubits valgus (forearm is angles away from body)

underdeveloped ovaries

late or incomplete puberty

infertility

17
Q

conditions associated with Turner syndrome

A

coarctation of the aorta

recurrent UTIs

recurrent otitis media

hypothyroidism

hypertension

obesity

diabetes

osteoporosis

18
Q

management of Turner syndrome

A

growth hormone therapy - prevents short stature

oestrogen and progesterone replacement

fertility treatment

19
Q

what is Marfan syndrome

A

autosomal dominant condition affecting fibrillin production

20
Q

features of Marfan’s

A
tall stature 
long neck
long limbs 
long fingers
high arch palate
hyper mobility 
pectus carinatum or pectus excavatum 
downward sloping palpebral fissures
21
Q

what are the tests for achrodactyly (long fingers)

A

ask patient to cross thumb across palm - if it extends past the opposite edge of the palm its arachnofactyly

wrap thumb and finger around wrist - if they overlap its acrodactyly

22
Q

conditions associated with Marfan’s

A
lens dislocation in eye
joint dislocations
scoliosis 
pneumothorax
GORD
mitral valve prolapse (with regurg)
aortic valve prolapse (with regurg)
aortic aneurysms
23
Q

management

A

treat cardiac risk factors
physiotherapy
genetic counselling
yearly echocardiograms and ophthalmology review

24
Q

what is fragile X syndrome

A

mutation in FMR1 gene on X chromosome

25
Q

features of fragile X syndrome

A
intellectual disability 
long narrow face
large ears
large testicles after puberty 
hyper mobile joints
ADHD
Autism 
seizures
26
Q

management of fragile X syndrome

A

supportive

manage autism and ADHD - treat seizures

27
Q

what is Prader-Willi syndrome

A

loss of genes on proximal arm of chromosome 15

28
Q

features of prader-willi syndrome

A
constant hunger than leads to obesity 
poor muscle tone
mild-mod learning disability 
hypogonadism 
fair soft skin 
mental health problems
dysmorphic features
narrow forehead
almond shaped eyes
strabismus
thin upper lip 
downturned mouth
29
Q

management of Prader-Willi syndrome

A

weight control with limited access to foods
growth hormone - improves muscle development

supportive care from MDT

30
Q

what is angelman syndrome

A

loss of UBE3A gene on chromosome 15

31
Q

features of angelman syndrome

A
developmental delay
learning disability 
speech delay or absence
ataxia
fascination with water
happy demeanour 
inappropriate laughter 
hand flapping 
abnormal sleep patterns
epilepsy 
ADHD
dysmorphic features
microcephaly 
fair skin, light hair, blue eyes
wide mouth - widely spaced teeth
32
Q

management of angelman syndrome

A

supportive from MDT

33
Q

what is William Syndrome

A

deletion of genes on chromosome 7 - random deletion not usually inherited

34
Q

features of William syndrome

A
broad forehead 
starburst eyes (stay pattern on iris) 
flattened nasal bridge
long philtrum
 wide mouth and widely spaced teeth
small chin 
very sociable and trusting 
mild learning disability
35
Q

conditions associated with William syndrome

A

supravalvular aortic stenosis (narrowing above the aortic valve)

ADHD

hypertension

HYPERCALCAEMIA

36
Q

what is Edward’s syndrome

A

trisomy 18

37
Q

how does Edward’s syndrome present

A

low set ears
rocker bottom feet
overlapping of fingers
micrognathia (v small lower jaw)

38
Q

what is patau syndrome

A

trisomy 13

39
Q

how does patau syndrome present

A
rocker bottom feet 
microphonic - small eyes
cleft lip/palate
polydactyly 
scalp lesions