Genetics Flashcards
(50 cards)
Klinefelter Syndrome
An additional X chromosome for men making them 47 XXY
Presentation of Klinefelter Syndrome
- Taller height - Wide hips - Gynaecomastia
- Weaker muscles
- Small testicles
- Reduced libido
- Shyness
- Infertility
- Subtle learning difficulties
Management of Klinefelter Syndrome
Testosterone injections - Advanced IVF techniques can potentially allow for IVF - Breast reduction surgery - MDT input to improve speech, language, strengthen muscles and provide education support.
Complications of Klinefelter Syndrome
There is an increased risk of breast cancer, osteoporosis, diabetes and anxiety
Turners Syndrome
Occurs when a female has a single X chromosome, making them 45 XO
Presentation of Turners Syndrome
- Short stature - Webbed neck - Widely spaced nipples with broad chest - High arching palate - Downward sloping with ptosis - Underdeveloped ovaries with reduced function - Late or incomplete puberty - Most women are infertile
Associated Conditions with Turners Syndrome
Recurrent otitis media
Recurrent UTI
Hypothyroidism
Hypotension
Obesity
Diabetes
Management of Turners Syndrome
Growth hormone therapy can help with short stature - Oestrogen and progesterone replacement can help establish female sex characteristics, regulate menstrual cycle and prevent osteoporosis - Regular monitoring is needed for the associated conditions
Complications of Turners Syndrome
aortic problems
osteoporosis
autoimmune conditions
frequent otitis media
eye problems
horseshoe kidney
bicuspid aortic valve
Downs Syndrome
3 copies of chromosome 21
Presentation of Downs Syndrome
Hypotonia
Small head with flat back
Short neck
Short stature
Flattened face and nose
Low set ears
Single palmar crease
Prominent epicanthic folds (folds of skin covering the medial portion of the eye and eyelid)
Upward sloping palpebral fissures (gaps between the upper and lower eyelid)
Ix for Downs Syndrome
Antenatal Screening, Combined Test, Triple Test, Quadruple Test
Antenatal Screening for Downs Syndrome
This is offered to screen for chances of Down’s syndromes where further investigations will take place if necessary. Older mothers generally have a higher risk
Combined Test for Downs Syndrome
Performed at 11-14 weeks gestation and combines ultrasound results looking at thickness on the back of the neck of the foetus (thickened) and beta-HCG (raised) and PAPPA (reduced)
Triple Test for Downs Syndrome
Performed at 14-20 weeks and looks at beta-HCG (raised), AFP (low) and serum oestriol (low)
Quadruple Test for Downs Syndrome
- Same as triple test but also includes inhibin-A (high)
Management of Downs Syndrome
MDT approach involves every medical professional and regular screening of the complications include echo, regular thyroid checks, regular eye checks and audiometry
Complications of Downs Syndrome
Learning disability
Recurrent otitis media
Deafness
Visual problems such as strabismus
Hypothyroidism
Cardiac defects such as ASD, VSD
Leukaemia
Dementia
Edwards Syndrome
Trisomy 18
Presentation of Edwards Syndrome
Low birthweight
Small mouth and chin
Short sternum
Flexed, overlapping fingers
‘Rocker-bottom feet’
Cardiac and renal malformations
Complications of Edwards Syndrome
90% have heart defect (PDA, ToF, CoA)
developmental delays and severe learning disability
decreased muscle tone
decreased tone in airways
Prognosis of Edwards Syndrome
Most die before birth, some can live up to a year
3 types of Edwards Syndrome
Full , Partial, Mosaic
Patau Syndrome
Trisomy 13