Genetic conditions Flashcards
DOWNS SYNDROME
i) name four dysmorphic features seen? name five complications
ii) what is the first line screening test in utero? when is it done? which two things does it involve?
iii) what three maternal blood tests does the triple test include? when is it done? what extra blood does the quadruple test include? when is it done?
i) hypotonia, brachycephaly (small head flat back), short neck, short stature, flat face, prominent epicanthic folds (skin ovr medial eye), upward slope palpebral fissures (gaps between lower and upper eyelid), single palmar crease
complications: learning disability, recurrent otitis media, deafness (glue ear and conductive hearing loss due to eustachian tube defects), visial probsm hypothyroid, cardiac defects (ASD, VSD, PDA, TOF), leuk, dementia
ii) first line is combined test at 11-14 weeks combines US and maternal blood tests
US measures nuchal translucency (>6mm)
bloods - beta HCG (high) and PAPPA (low)
iii) triple test 14-20 weeks (only maternal blood)
beta HCG (high), AFP (low), serum oestriol (low)
quadruple also looks at inhinin A (high)
DOWNS SYNDROME CONTINUED
i) greater than what risk score will lead to a woman being offered amniocentesis or CVS? what does each involve?
ii) what is NIPT? who is it offered to?
iii) name three regular routine checks for children with DS
i) risk of 1 in 150 > amnio/CVS
amnio - US guided aspiration of am fluid to karyotype anal
CVS - US biopsy of placental tissue (earlier before 15 weeks)
ii) NIPT offered to women higher than 1 in 150 change > test blood for fetal DNA
iii) routine thyroid checks (hypothyroid), ECG for cardiac defects, audiometry for hearing imapir, regular eye checks
KLIENFELTER SYNDROME
i) who does it occur in? what is genotype? when may they appear normal until?
ii) name four features that may be seen?
iii) name three things that can be done to manage symptoms?
iv) do they have normal life expectancy? name three things they are at slight increased risk of
i) occurs in males with additional X chromo > XXY
may appear normal until puberty
ii) tall, wide hips, GCM, weak musc, small testicles, reduced libido, infertility
iii) testosterone injections, IVF for fertility, breast reduction surgery
iv) normal life expec
inc risk of breast cancer, osteoporosism diabetes
(think female symptoms in male)
TURNER SYNDROME
i) who does it occur in? what is the genotype? what is life expec?
ii) name five features? how may the elbow appear?
iii) name four associated conditions
iv) name three treatments that can be given to help symptoms?
v) which two heart defects may be seen? which murmur can be heard if present
i) females with a single X chromo - XO
normal life expec
ii) short, webbed neck, high palate, down slope eyes, broad chest w wide space nipples, undrdev ovaries, late puberty, infertilty
elbow = cubital valgus (elbow angled away from body)
iii) recurrent otitis media, rec UTI, coarc aorta, hypothyroid, high BP, obesity, diabtetes, osteoporosis
iv) GH therapy to prevent short stature, oes and proges for female sex charac, fertility tx
v) see coarctation of aorta and bicuspid aortic valve > ejection systolic murmur
NOONAN SYNDROME
i) how is it inherited? name four features?
ii) name four associated conditions? how is fertility affected
iii) how is it managed? what is the main complication?
i) auto dominant - number of diff genes cause it
features - short, broad forehead, down slope yeyes, hypertelorism (wide space between eyes)
ii) congen heart disease (pulm stenm hypertrophic CM, ASD), undesc testes, learning disability, bleeding disorder, lymphoedema, leuk and NBL increased risk
male may have infert but female normal fertility
iii) MDT appraoch and supportive
complicat is congenital heart disease > may need corrective sx
MARFAN SYNDROME
i) what gene is responsible? what is inheritance pattern?
ii) name four features? what heart condition may be seen?
iii) name three assoc conditions
iv) what is the greatest risk to the patient? why may medications like beta blockers be given?
v) why should pregnancy be carefully considered? what follow up should patients have annually?
i) auto dominant > fibrillin gene > abnormal connective tissue
ii) tall, long neck, long limb, long fingers, high palate, hypermobile, pectus excavartum
long fingers (get thumb to cross palm, wrap fingers around wrist)
iii) lens disloc in eye, joint disloc, scoliosis, pneymothorax, GORD, mitral/aortic valve prolapse and regurg, aortic aneurysm
iv) greatest risk is cardiac complications eg valve prolapse and aortic aneurysm
give beta blockers etc to minimise stress on the heart
v) carefully consider preg due to signif risk of aortic aneurysms
follow up echo and review opthalmology annually
FRAGILE X SYNDROME
i) what gene is mutated? what is inheritance? which sex are always affected if they have it?
ii) how does it usually present? name four other features
i) FMR1 gene on X chromosome - X linked
FMR1 plats a role in cognitive brain development
males always affected but females vary
ii) usually px with delay in speech and language
also see intellectual disability, long narrow face, large ears, large testicles post puberty, hypermobile, ADHD, autism, seizure
PRADER WILLI SYNDROME
i) what is it caused by?
ii) what is a key px feature? name three others
iii) what hormone tx is indicated by NICE? which MDT member plays an important role
i) caused by loss of functional genes on proximal arm of chromo 15 inherited from father
ii) constant insatiable hunger > obesity
also see hypotonia, learning dis, hypogonad, fair soft skin, MH problems, dyspmorphic features, almond shaped eyes, stabismus
iii) growth hormone tx to improve muscle development and body composition
dietitcian is very important
ANGELMAN SYNDROME
i) what is it caused by? what chromosome can be implicated?
ii) name five features? what are two key features
i) caused by loss of function of UBE3A gene from mother > can be due to deletion on chromo 15
ii) fascination with water, happy demenour, delated edv, wide spaced teeth, co ord problems, hand flap ADHD, microcephaly
WILLIAM SYNDROME
i) what is it caused by? is it inherited?
ii) name three features? what is key feature?
iii) what heart condition can be assoc? name two other associations
iv) which two things should be monitored? what type of diet should be followed?
i) deletion of genetic material on chromo 7 due to random deletion around conception (not inherited)
ii) starburst eyes, sociable, broad forehead, long philtrum, small chin, wide mouth, big smile
iii) assoc with supravalvular aortic stenosis, ADHD, hypertension and hypercalcaemia
iv) echo and BP monitooring
follow low calcium diet - avoid calcium and vitamin D supplements
