Genetic Conditions Flashcards
Down syndrome
Trisomy 21
Dysmorphic features and mild-to-severe cognitive impairment
Combined test for Down’s syndrome
11-14 weeks gestation
USS: Nuchal thickness over 6mm
Beta-HCG: high result
Pregnancy-associated plasma protein: lower result
Triple test Down’s syndrome
14-20weeks gestation
Beta-HCG: higher result indicates a greater risk
AFP: lower result indicates a greater risk
Serum oestriol: lower result indicates a greater risk
Quadruple test for Down’s syndrome
Beta-HCG: higher
AFP: lower
Serum oestriol: lower
Inhibin-A: higher
Antenatal screening for Down’s syndrome
Combined test
Triple test
Quadruple tests
Antenatal testing for Down’s syndrome
If risk score from screening is greater than 1 in 150
Amniocentesis if >15weeks
Chorionic villus sampling if <13weeks
Dysmorphic features of Down syndrome
Hypotonia (reduced muscle tone) Brachycephaly (small head with flat back) Short neck Short stature Flattened face and nose Prominent epicanthic folds Upwards sloping palpable fissures Single palmar crease Small mouth, with relative macroglossia
Complications of Down syndrome
Visual problems: congenital cataract, infantile glaucoma, strabismus and nystagmus
Hearing difficulties- predominantly conductive hearing loss
ENT: OSA, increased risk of infections
Cardiac abnormalities: AVSD
GI: oesophageal atresia, tracheo-oesophageal fistula, duodenal atresia, imperforate anus, Hirschprung’s
MSK: hypotonia, risk of Atlanto-axial dislocation,
Growth and development: poor growth and short status are common
Endocrine: hypothyroidism
Haematological: transient myeloproliferative disorder, acute myeloid leukaemia
OSA complications
Day-time Somnolence Obesity HTN Eventual risk or cor pulmonale
Differential diagnosis of Down’s syndrome
Trisomy 13, Patau
Trisomy 18, Edwards
Trisomy 21 Down
Early management of Down’s syndrome
Senior paediatrician and midwife to attend to the family
Tell it Right, Start it right
Early counselling
Blood tests: QF-PCR, followed by G-banded analysis to identify trisomy 21, FBC and blood film (DSA neonatal)
Newborn eye assessment
Universal newborn hearing screen
Guthrie test- new born blood spot on day 5 to screen for congenital hypothyroidism
ECG and ECHO
Down syndrome checks birth-6 weeks
TFTs: newborn routine heel prick- blood spot test
Eye checks: congenital cardiac check
Hearing checks: universal newborn hearing screen
Growth monitoring: length, weight and head circumference
Heart checks, ECHO
Breathing checks: enquire at every review for uneven breathing during sleep and poor quality intake, low threshold for further testing using sleep studies
Blood checks: newborn blood test to check for abnormal blood film
Down syndrome special checks under 2 years
Annual fingerprick TSH test
2 yearly thyroid blood tests, including thyroid antibodies
Eye and vision exam: check for squint, refraction for long or short sight
Visual behavior to be monitored every year
Full audiologial review by 10 months including hearing test and impedance check
Length, weight and head circumference
Heart checks
B reaching checks
Blood checks until age of 5
Complications of Down’s syndrome
Life expectancy reduced to 60 years
Increased incidence of Alzheimer’s dementia
Non-invasive prenatal testing
Tests mother’s blood for fragments of DNA
Routine follow-up investigations for children with Down’s syndrome
Regular thyroid checks
Echocardiogram to diagnose cardiac defects
Regular audiometry for hearing impairment
Regular eye checks
Causes of cerebral palsy
Antenatal: maternal infections, trauma during pregnancy
Perinatal: birth asphyxia, pre-term birth
Postnatal: meningitis, severe neonatal jaundice, head injury
Types of cerebral palsy
Spastic
Dyskinetic
Ataxic
Mixed
Spastic cerebral palsy
Hypertonia
Pyramidal CP
Reduced function resulting from damage to UMN
Dyskinetic cerebral palsy
Problems controlling muscle tone
Hypertonia and hypotonia
Causing athetoid (slow) movements an oro-motor problems
This is a result of damage to the basal ganglia
Athetoid CP and extrapyramidal CP
Ataxic cerebral palsy
Problems with uncoordinated movement resulting from damage to the cerebellum
Shaky movements
Affects balance nad sense of position in space
Patterns of spastic cerebral palsy
Monoplegia: one limb affected
Hemiplegia: one side of the body affected
Diplegia: four limbs are affected, but mostly the legs
Quadriplegia: four limbs are affected more severely, often with seizures, speech disturbance and other impairments
Which children are at risk of developing cerebral palsy?
Those with hypoxic-ischaemic encephalopathy
Signs and symptoms of cerebral palsy
Failure to meet milestones
Increased or decreased tone, generally or in specific limbs
Hand preferences below 18months
Problems with coordination, speech or walking
Feeding or swallowing problems
Learning difficulties
