genetics Flashcards
clinical features of downs
hypotonic
single palmar crease
small stature
incurved 5th finger
dysmorphic features
dysmorphic features in downs
round face and flat nasal bridge
upslanted palpebral fissure
epicanthic folds
small mouth and protruding tongue
small ears
what does the combined screening test for and when does it happen
downs, edwards and pataus
10-14weeks
what is edwards syndrome and prognosis
trisomy 18
most end in miscarriage or stillbirth
what does turner syndrome mainly affect
height and sexual development
shorter than average and underdeveloped ovaries - lack of monthly periods and infertility
what does turner syndrome also result in (clinical presentation)
neck webbing
spoon shaped nails
widely spaced nipples
congenital heart defects
management for turner syndrome
growth hormone therapy
oestrogen replacement
what is klinefelter syndrome
extra X chromosome- 45 XXY
affects sexual, physical and intellectual development
clinical presentation of klinefelter syndrome- physical
- tall stature
- low muscle tone and strength
- long arms and long legs
- less facial and body hair
- broad hips
clinical presentation of klinefelter syndrome- sexual
- small penis and testicles
- gynecomastia
- infertility
health issues in klinefelters
DMT2
osteoporosis
heart disease and blood clots
male breast cancer
management for klinefelters
testosterone replacement therapy
physio
fertility treatment
breast reduction
psychological support
what is fragile X syndrome
x linked recessive disorder causing a mutation in the FMR1 gene
causes learning difficulties and social and behaviour problems
clinical features of fragile X syndrome
autism and ADHD
delay in speech and language development
learning difficulties
macrocephaly
large testicles after puberty
characteristic faces in fragile X syndrome
large everted ears
broad forehead
long face
what is prader-willi syndrome
genetic condition caused by the loss of functional genes on the proximal arm of chromosome 15 inherited from the father
normal physiology of long arm of chromosome 15
imprinting- long arm of chromosome 15 from the mother is imprinted (deleted) so only the father’s is expressed
pathophysiology of prader-willi syndrome
deletion of paternal prader-willi genes
mutation of imprinting mechanism
maternal uniparental disomy
clincial features of prader-willi syndrome
hyperphagia
short
high pain and vomiting tolerance
hypotonia as an infant
mild/ moderate learning disability
fair soft skin prone to bruising
characteristic face in prader willi syndrome
almond shaped eyes
narrow forehead
strabismus
thin upper lip
downturned mouth
management of prader-willi syndrome
growth hormone
managing weight
limit access to food
what are patients with prader-willi syndrome at a higher risk of
food poisoning
choking
stomach rupture
what is noonan syndrome
autosomal dominant
affects normal development in various parts of the body
associated conditions in noonan syndrome
congenital heart disease
learning disabilities
bleeding disorders
increased risk of leukaemia
