Paediatrics: Genetics

Question 1

What is mocaism ?

Answer 1

chromosomal abnormality occurs after conception (occurs in some cell + not others) => different genetic material in different cells in body

Question 2

What is patau syndrome ? what chromosome affected ?

Answer 2

genetic abnormality - trisomy 13

Question 3

patau and Edwards syndrome features ?

Answer 3

• Dysmorphic features
• Structural Abnormailites
• LD
• Rocker bottom feet
  (quite similar presentation)

Question 4

what is Edwards syndrome ? what chromosome affected ?

Answer 4

trisomy 18

Question 5

what is the prognosis for patios and Edwards syndromes ?

Answer 5

babies usually do not survive longer than a week
- about 10% live to 5 yrs
(about the same for both)

Question 6

what are the dysmophric symptoms of Down’s syndrome ? (8)

Answer 6

• Flattened face
• almond shaped eyes that slant up
• short neck
• small ears
• prominent epicantic folds
• single palmar crease
• tongue tends to stick out of mouth
• increased gap between great toe and first toes

Question 7

Complications of downs syndrome ?

Answer 7

• LD
• recurrent otitis media
• Deafness
• visual prblems
• Cardiac defects
• leukaemia
• dementia

Question 8

what cardiac defects are associated with trisomy 21 ?

Answer 8

AVSD
ASD
VSD
PDA
ToF

Question 9

downs syndrome management ? (4)

Answer 9

MDT approach
- Routine follow up: thyroid checks, echo, auditory, eye checks

Question 10

What is Kleinfelter syndrome ? what chromosome affected ? males or females affected ?

Answer 10

occurs when male has an additional X chromosome (47 XXY)
(or 48 XXXY, 49 XXXXY)

Question 11

features of kleifelters syndrome ? what age does it typically present ? (8)

Answer 11

appear as normal males until puberty
- Taller height
- Wider hips
- Gynaecomastia
- weak muscles
- small testicles
- low libido
- Infertility
- Subtle LD

Question 12

kelinfelter syndrome managment ? (3)

Answer 12

no treatment
- Testosterone injections, IVF, breast reduction surgery

Question 13

Down syndrome prognosis ? (life expectancy)

Answer 13

life expectancy: 60 yrs

Question 14

Kleinfelter life expectancy ?

Answer 14

close to normal

Question 15

What is Turner syndrome ? what chromosome affected ? males or females affected ?

Answer 15

occurs when a female has a single X chromosome (45 XO)

Question 16

Turner syndrome features ? Maine 3 ? (6)

Answer 16

• Short stature
• Webbed neck
• Wide spaced nipples
• underdeveloped ovaries with reduced function
• late puberty
• infertility

Question 17

complications of turners syndrome ? (6)

Answer 17

• recurrent otitis media
• Recurrent UTI
• Coarctation of the aorta
• Hypothyroidism
• DM
• LD

Question 18

Turner syndrome management ?

Answer 18

• GH therapy (short stature)
• Oestrogen + progesterone (secondary sex characteristics + regulate menstrual cycle)
• Fertility treatment

Question 19

What is Noonan syndrome ? what chromosome ? what inheritance ?

Answer 19

genetic condition caused by several different genes
- mostly autosomal dominant

Question 20

Noonan syndrome features ? (6)

Answer 20

• Short stature
• Broad forehead
• Wide spaced eyes
• Low set ears
• Webbed neck
• Widely spaced nipples

Question 21

what is fragile x syndrome ? what chromosome ? what inheritance ?

Answer 21

caused by a mutation in the FMR1 gene (fragile Mental retardation 1 gene) on chromosome X
- x-linked condition (unclear if dominant or recessive)

Question 22

fragile x syndrome features ?

Answer 22

• usually present with delay in speech + language
• LD
• Long narrow face
• Large ears
• Large testicles
• ADHD/ASD
• Seizures

Question 23

fragile x syndrome management ?

Answer 23

supportive + treating symptoms

Question 24

What is Prader-Willi syndrome ? what chromosome ?

Answer 24

genetic condition caused by loss of functional genes of proximal arm of chromosome 15 inherited from father

Question 25

Prader-Willi syndrome features ?

Answer 25

- constant insatiable hunger (=> obesity) - hypotonia - Mild-mod LD - Hypogonadism - Anxiety

Question 26

Prader-Willi management ? (2)

Answer 26

MDT approach - limit access to food to control weight - GH (to improve muscle dev + body composition)

Question 27

What is Angelman syndrome ? which chromosome ?

Answer 27

loss of function of UBEA3A gene on chromosome 15

Question 28

Angelman syndrome features ?

Answer 28

- fascination with water - Happy demenour - Widely spaced teeth - epilepsy

Question 29

what is William syndrome ? what chromosome affected ?

Answer 29

caused by deletion of genetic material on one copy of chromosome 7

Question 30

William syndrome features ?

Answer 30

- very sociable personality (trusting) - Starburst eyes - Wide mouth (big smile) - LD

Question 31

what is William syndrome associated with ? What heart murmur?

Answer 31

- supravalvular aortic stenosis - Hypercalcaemia

Question 32

William syndrome manamgnet ? (1)

Answer 32

MDT approach - low calcium diet (due to prone to hypercalcaemia)

Question 33

What is Kallman syndrome ?

Answer 33

Kallman syndrome is a genetic condition causing hypogonadotrophic hypogonadism, resulting in failure to start puberty. It is associated with a reduced or absent sense of smell (anosmia).

Question 34

A young boy is noted to have a webbed neck, pulmonary stenosis, ptosis and short stature. The karyotype is normal. what is this?

Answer 34

Noonan syndrome