Genetics

Question 1

Define Down’s Syndrome

Answer 1

Genetic condition caused by three copies of chromosome 21 - trisomy 21

Question 2

Typical features in Down’s syndrome

Answer 2

Hypotonia
Bradycephaly
Short neck
Short stature
Flattened face and nose
Prominent epicanthic folds
Upward sloping palpebral fissures
Single palmar crease

Question 3

Complications of Down’s syndrome

Answer 3

Learning disability
Recurrent otitis media
Feadness - eustachian tube defects
Visual problems - myopia, strabismus and cataracts
Hypothyroidism
Cardiac defects - ASD, VSD, patent ductus arteriosus and tetralogy of fallot
Atlantoaxial instability
Leukaemia
Dementia

Question 4

When is a combined screen carried out

Answer 4

Between 11 and 14 weeks

Question 5

What is assessed in combined screen

Answer 5

Looking for downs
US measure of nuchal translucency - increased
Beta-HCG - increased
Pregnancy associated plasma protein - decreased

Question 6

What is assessed in the tripple test

Answer 6

Looking for Downs
Beta-HCH - increased
Alpha-fetoprotein - decreased
Serum oestriol - decreased

Question 7

When is a triple test done

Answer 7

14-20 weeks

Question 8

What is assessed in a quadruple test

Answer 8

Looking for Downs
Beta-HCH - increased
Alpha-fetoprotein - decreased
Serum oestriol - decreased
Inhibin-A

Question 9

When is a quadruple test done

Answer 9

14-20 weeks

Question 10

When are amniocentesis and CVS offered

Answer 10

When risk of Downs is greater the 1 in 150

Question 11

When can CVS be done

Answer 11

Before 15 weeks -

Question 12

Management of Downs syndrome

Answer 12

MDT!
Thyroid checks
Echocardiogram
Audiometry
Eye checks

Question 13

Define Klinefelter syndrome

Answer 13

Occurs where a male has an additional X chromosome - 47 XXY

Question 14

Typical features of Kleinfelter syndrome

Answer 14

Devlop features at puberty
Taller
Wider hips
Gynaecomastia
Weaker muscles
Small testicles
Reduced libido
Shyness
Infertility
Subtle learning difficulties

Question 15

Management of Kleinfelter syndrome

Answer 15

No cure
Testosterone injections
Advanced IVF techniques
Breast reduction
Speech and language
Occupational therapy
Physio
Educational support

Question 16

Define Turner syndrome

Answer 16

Occurs when a female has a single X chromosome - 45 XO

Question 17

Classic features of Turner syndrome

Answer 17

Short stature
Webbed neck
Widely spaced nipples
High arching palate
Downward sloping eyes with ptosis
Broad chest
Cubitus valgus - arms out at elbows
Underdeveloped ovaries with reduced function
Late or incomplete puberty
Infetile

Question 18

What conditions are associated with Turner syndrome

Answer 18

Recurrent otitis media
Recurrent UTI
Coarctation of the aorta
Hypothyroidism
Hypertension
Obesity
Diabetes
Osteoporosis
Various specific learning disabilities

Question 19

Management of Turner syndrome

Answer 19

Growth hormone therapy
Oestrogen and progesterone replacement - sex characteristics, regulate menstrual cycle
Fertility treatment

Question 20

Define Noonan syndrome

Answer 20

Genetic condition predominantly caused by autosomal dominant variation

Question 21

Classic features of Noonan syndrome

Answer 21

Short stature
Broard forehead
Downward sloping eyes with ptosis
Hypertelorism - wide eye spacing
Prominent nasolabial folds
Low set ears
Webbed neck
Widely spaced nipples

Question 22

Conditions associated with Noonan syndrome

Answer 22

Congenital heart disease - pulmonary valve stenosis, hypertrophic cardiomyopathy, ASD
Crytorchidism
Learning disability
Bleeding disorders
Lymphoedema
Leukaemia and neuroblastoma

Question 23

Define Marfan syndrome

Answer 23

An autosomal dominant condition affecing the gene responsible for creating fibrillin - an important component of connective tissue

Question 24

Classic features of Marfan syndrome

Answer 24

Tall stature
Long neck
Long limbs
Long fingers
High arching palate
Hypermobility
Pectus carinatum or pectus excavatum
Downward sloping palpable fissure

Question 25

Conditions associated with Marfans syndrome

Answer 25

Lens dislocation in the eye Joint dislocations and pain due to hypermobility Scoliosis Pneumothorax GORD Mitral valve prolapse Aortic valve prpolapse Aortic aneurysms

Question 26

Define fragile X syndrome

Answer 26

Caused by a mutation in the FMR1 gene on the x chromosome - plays a role in cognitive development X linked - dominant or recessive

Question 27

Classic features of Fragile X syndrome

Answer 27

Intellectual disability Long narrow face Large ears Large testicles after puberty Hypermobility - esp hands ADHD Autism Seizures

Question 28

Define Prader Willi syndrome

Answer 28

A genetic condition caused by the loss of functional genes on the proximal arm of chromosome 15 Due to a deletion

Question 29

Classic features of Prader-Willi syndrome

Answer 29

Constant insatiable hunger - obesity Poor muscle tone Mild-moderate learning disability Hypogonadism Fairer soft skin Prone to bruising Mental health issues - anxiety Dysmorphic features Narrow forehead Almond shaped eyes Strabismus Thin upper lip Downturned mouth

Question 30

Management of Prader-Willi syndrome

Answer 30

Locking cupboards Growth hormone - improves muscle development Supportive care

Question 31

Define Angelman syndrome

Answer 31

A genetic condition caused by loss of function of the UBE3A gene - inherited from the mother - deletion on chromosome 15

Question 32

Classic features of Angelman syndrome

Answer 32

Fascination with water Happy demeanour Widely spaced teeth Delayed development - esp speech Coordination and balance problems Inappropriate laughter Hand flapping Abnormla sleep Epilepsy ADHD Dysmorphic features Microcephaly Fair skin Light skin Wide mouth

Question 33

Define William syndrome

Answer 33

Caused by random deletion of genetic material on one copy of chromosome 7

Question 34

Classic features of William syndrome

Answer 34

Very sociable Broad forehead Starburst eyes Associated with supravalvular aortic stenosis Flattened nasal bridge Long philtrum Wide mouth with widely spaced teeth Small chin