Genetic Syndromes

Question 1

What genetic mutation causes Down’s syndrome

Answer 1

3 copies of chromosome 21 - Trisomy 21

Question 2

Dysmorphic features associated with Down’s

Answer 2

Hypotonia, short neck, brachycephaly, short stature, flattened face and nose, prominent epicanthic folds, upward sloping palprebral fissures, single palmar crease

Question 3

Complications of Down’s syndrome

Answer 3

Learning disabilities, recurrent otitis media, deafness and eustachian tube abnormalities, visual problems (myopia, strabismus, cataracts), hypothyroidism, cardiac defects, atlantoaxial instability, leukaemia, dementia

Question 4

Inheritance of Noonan syndrome

Answer 4

Autosomal dominant

Question 5

Features of Noonan syndrome

Answer 5

Short stature, broad forehead, downward sloping eyes with ptosis, hypertelorism, prominent nasalabial folds, webbed neck, widely spaced nipples and low set ears

Question 6

Associations with Noonan syndrome

Answer 6

Congenital heart disease, Cryptorchidism (can lead to infertility), learning disabilities, lymphoedema, increased risk of leukaemia and neuroblastoma

Question 7

Genetic mutation in Turner’s syndrome

Answer 7

Female has single X chromosome

Question 8

Features of Turner’s syndrome

Answer 8

Short stature, webbed neck, high arching palate, downwards sloping eyes with ptosis, broad chest with widely spaced nipples, cubitus valgus, underdeveloped ovaries with reduced function, late or incomplete puberty, infertile mostly

Question 9

Conditions associated with Turner’s syndrome

Answer 9

Recurrent otitis media, UTIs, coarctation of the aorta, hypothyroidism, hypertension, obesity, diabetes, osteoporosis, various specific learning disabilities

Question 10

Management of Turner’s syndrome

Answer 10

GH therapy, oestrogen and progesterone, fertility treatment, monitor complications and conditions

Question 11

Genetic mutation in Klinefelters

Answer 11

Male has additional X chromosome, and can have more than just one extra X with more severe features

Question 12

Features of Klinefelters

Answer 12

Taller height, wider hips, gynaecomastia, weaker muscles, small testicles, reduced libido, shyness, infertility, subtle learning difficulties, appear normal untill puberty

Question 13

Management of Klinefelters

Answer 13

Testosterone injections, advanced IVF techniques, breast reduction surgery, MDT input

Question 14

What is the genetic mutation in Prader-Willi syndrome

Answer 14

Loss of functional genes on the proximal arm of the chromosome 15 inherited from the father

Question 15

Features of Prader-Willi syndrome

Answer 15

Constant irritable hunger leading to obesity, poor muscle tone as infant, mild-moderate learning disability, hypogonadism, fairer soften skin prone to bruising, mental health problems, dysmorphic features, narrow forehead, almond shaped eyes, strabismus, thin upper lip, downturned mouth

Question 16

Management of prader-wili syndrome

Answer 16

GH aims at improving muscle development and body composition, dieticians to stop overeating

Question 17

What mutation causes Marfan syndrome

Answer 17

Autosomal dominant condition affecting gene responsible for fibrillin leading to abnormal connective tissue

Question 18

Features of Marfan’s

Answer 18

Tall stature, long neck, limbs and finegrs, hypermobility, high arched palate, pectus carinatum or excavatum, downsloping palpable fissures

Question 19

Conditions associated with Marfans

Answer 19

Lens discolouration in the eye
Joint dislocation and pain
Scoliosis of spine
Pneumothorax
GORD
mitral valve prolapse
Aortic valve prolapse
Aortic aneurysms

Question 20

Management of Marfans

Answer 20

Monitor cardiac complications, minimise BP and HR to reduce stress on heart, ARB, beta blockers, physiom ECHO, opthalmology, pregnancy can have serious complications

Question 21

Genetic mutation in fragile X syndrome

Answer 21

Mutation in FMR1 gene on chromosome X which has role in cognitive brain development

Question 22

Features of fragile X syndrome

Answer 22

Intellectual disability, delay in speech and language development, long narrow face, large ears, large testicles after puberty, hypermobile joints, ADHD, autism, seizures

Question 23

What is the genetic mutation in Angelman syndrome

Answer 23

Loss of function in the UBE3A gene, specifically the copy which is inherited from the mother

Question 23

Features of Angelman syndrome

Answer 23

Delayed development and learning disability, severe delay or absense of speech development, ataxia, fascination with water, happy demenour, innapropriate laughter, hand flapping, abnormal sleep patterns, epilepsy, ADHD, dysmorphic features, microcephaly, fair skin, light hair, blue eyes, wide mouth, widely spaced teeth

Question 24

What is the genetic mutation in William syndrome

Answer 24

Deletion of one copy of chromosome 7

Question 25

Features of william syndrome

Answer 25

Broad forehead, starburst eyes, flattened nasal bridge, long philtrum, wide mouth, widely spaced teeth, small chin, very sociable and trusting, mild learning disability

Question 26

Associated conditions with Wiliam syndrome

Answer 26

Supraventricular aortic stenosis, ADHD, HTN, hypercalacemia