Genetics Flashcards
Give 5 signs that a baby may have downs syndrome
- flat occiput
- dysmorphic round face
- epicanthic folds
- protruding tongue
- short neck, aubundant neck skin
- small ears
- single palmer crease
- incureved little fingers
- gap between 1st and 2nd toes (sandle toe)
- floppiness
- brushfeild’s (white) spots on iris
Give 6 common complications of downs syndrome
- GI defects: duodenal atresia, reflux, coeliac
- heart defects: VSD, PDA, ASD
- hypothyroidism
- leukaemia
- low IQ, developmental delay
- alzheimers
- immune disorders: cancer and infections
- sleep apnoea
- obesity
- atlantoanxial instability
- endocrine, dental, vision and hearing problems
Describe the screening tests for downs
- blood test in pregnancy looking for plasma protein A and Hcg
- nuchal translucency test on USS
- tripple test if later (HCG, AFP, PAPP-A, DA, uE3)
Describe the diagnostic tests for downs (before and after birth)
before: - chorionic villus sampling - amniocentesis after: - clinical and karyotype diagnosis
How should downs be managed?
- MDT approach
- monitor and treat complications
- educational plans- may need special educational needs school
- social groups and play groups for famillies experiencing the same issues
Give 3 RFs for downs syndrome
- advanced maternal age
- carrier of genetic translocation
- having one child with downs syndrome
Give 5 features of turners syndrome present at birth
- wide or web like neck
- low set ears
- broad chest w/ widely spaced nipples
- high narrow palate
- arms that turn outwards at elbows
- small and upturned finger and toenails
- swelling of hands and feet
- slow growth
- low hairline at back of head
- receeding or small lower jaw
Give 5 signs of turners syndrome that become evident as they grow up
- slow growth/ no growth spurt when expected
- short stature
- failure to begin sexual changes expected during puberty
- Sexual development which stalls during teenage years
- early end to menstrual cycles not due to pregnancy
- inability to conceive a child without fertility treatment
Give 3 possible signs on prenatal USS of baby with turners syndrome
- large fluid collection on back of neck or other abnormal collections of odema
- heart abnormalities
- abnormal kidneys
What is the pathophysiology of turners syndrome
- X chromosome is missing or partially missing
- may be monosomy, mosaicism, Xchromosome abnormalities or only partial Y chromosome material
List 7 complications commonly associated with turners syndrome
- heart defects (coarctation, bicuspid aortic valve)
- high BP
- hearing loss and frequent middle ear infections
- vision problems (particularly myopia)
- kidney problems (malformations eg duplex ureters and horseshoe)
- autoimmune disorders: hypothyroidism, diabetes
- skeletal problems eg scoliosis
- learning disabilities
- mental health issues and ADHD
- infertility
- pregnancy complications eg high BP or aortic dissection
Describe the 4 interventions needed for most patients with turners syndrome
- growth hormone: improve height and bone growth
- oxandrolone: increase height by increasing bodies production of protein, alone improved bone density
- oestrogen therapy: to initiate puberty, promote breast and uterus development and helps w/ bone density
- fertility treatment may be needed to become pregnant (clomifene)
Describe how duchenne’s muscular dystrophy presents
- progressive weakness and wasting of muscles, onset is 3-5 years old
- mostly affects males
- initial symptoms inc waddling gait, difficulty rising from lying position, trouble running and jumping, walking on toes, muscle pain and stiffness
- motor development delay and regression
- clumsiness, frequent falls, difficulty climbing stairs, riding bikes etc may be reported
- calf pseudohypertrophy
- gowers sign (need to turn onto front to rise)
How should suspected duchennes muscular dystrophy be investigated?
- CK (raised)
- electromyography: measures contractility
- genetic tests: for specific mutations
- muscle biopsy
- ECG/ echo to look for heart involvement
- lung function tests for baseline
Give 5 complications of duchennes muscular dystrophy
- trouble walking- needing wheelchair eventually
- contractures
- breathing problems due to muscle weakness, eventually needing ventilation
- scoliosis as weakened muscles cant hold spine straight
- heart failure
- swallowing problems and associated aspiration pneumonia
State 3 medications commonly used in muscular dystrophy and why they’re used
- eteplirsen: increases muscle strength
- corticosteroids: helps strength and delays progression of MD
- ACEi or Betablockers if damage to heart muscle
Other than medications, what else is important in the management of muscular dystrophe
- ROM and stretching exercises
- low impact aerobic exercises for strength, mobility and general health
- braces and splits to help avoid contractures
- mobility aids: canes, walkers and wheelchairs
- breathing exercises
- surgery for spinal curvature
- vaccinate for pneumonia and influenza
Describe the physical features of foetal alcohol syndrome
- microcephaly
- ‘railroad track’ ears
- flat midface
- small palpebral fissues
- epicanthal folds
- smooth philtrum
- underdeveloped jaw
- thin vermillion boarder
- upturned nose
- low nasal bridge
- joint/ limb deformities
- vision difficulties
- heart defects and kidney problems
- IUGA
- slow development
Describe the CNS features and social and behavioural issues associated with foetal alcohol syndrome
- poor coordination
- low IQ
- poor memory
- attention issues, hyperactivity
- rapidly changing mood
- poor judgement skills
- poor social skills
- poor impulse control
- poor concept of time
What defect causes marfans and what is its inheritance pattern
mutation in fibrillin-1 gene on chromosome 15, autosomal dominant inheritance
Describe the clinical features of marfans disease
- tall and slender build
- disproportionatley long arms (span exceeds height), legs and fingers
- pectus excavatum
- scoliosis
- upwards lens dislocation and myopia
- high arched palate
- hyperflexibility
- flat feet
- CVS disease: aortic dissection, mitral valve prolapse, aortic regurg
Give 5 complications of marfans disease
- aortic aneurysm
- aortic dissection
- valve disease
- lens dislocation
- retinal problems- detachment or tear
- early onset glaucoma or cateracts
- skeletal complications/ scoliosis
How is marfans managed?
- medications: to reduce BP and prevent aorta enlarging
- glasses and eye tests regularly
- CT/ MRI angio to moitor heart
- surgery to manage complications
What can PKU cause if not picked up at newborn screening?
- intellectual disability
- seizures
- behaviour problems
- skin rashes and eczema
- musty body odour
- fair skin and blue eyes (as phenylalanine isnt converted into melanin)
- microcephaly
- developmental delay
What foods need to be avoided in PKU?
- meat
- dairy
- dry beans
- nuts
- eggs
- cereals, fruits and veg in moderation
- PKU formula for nutritional support
Define achondroplasia
Short stature that results from a genetic or medical condition. Defined as an adult height of 4ft10inches or less. In achondroplasia, the short stature is disproportionate.
Describe the habitus of a pt with achondroplasia
- An average-size trunk
- Short arms and legs, with particularly short upper arms and upper legs
- Short fingers, often with a wide separation between the middle and ring fingers
- Limited mobility at the elbows
- A disproportionately large head, with a prominent forehead and a flattened bridge of the nose
- Progressive development of bowed legs
- Progressive development of swayed lower back
- An adult height around 4ft
State 5 complications of achondroplasia
- delays in motor development
- frequent ear infections and hearing loss risk
- bowing of legs
- sleep apnoea
- pressure on spinal cord at base of skull
- hydrocephalus
- crowded teeth
- back pain
- spinal canal stenosis
- arthritis
- weight gain
