Common congenital abnormalities Flashcards
What is the most common genetic cause of mental retardation?
Down’s syndrome
What can Down’s syndrome be caused by? (3)
94% - Non-dysjunction
5% - Robertsonion translocations
1% mosaicism
Trisomy 18 is known as?
Edward’s syndrome
Trisomy 13 is known as?
Patau syndrome
What are Edward’s and Patau associated wtih
multiple congenital defects and death occurs in utero or shortly after birth
When is Down’s usually picked up and using what?
1st trimester using combined test
or
at birth due to characterisic appearance and hypotonia - chromosomal studies
What are the RF for Down’s (3) increased…
- advanced maternal age
- previous affected child
- Increased NT, low PAPP-A, low AFP and high hCG, and structural abnormlaities especially cardiac
What are the clinical features of the face in the Down’s syndrome? (6)
- upslanting palpebral fissures
- epicanthic folds
- Brushfield spots in iris (ring of iris speckles)
- protruding tongue
- small ears
- round / flat face
What are the other features of Down’s syndrome?
- flat occiput
- single palmar creases - pronounced sandal slap
- Hypotonia
- Congenital heart defects
- duodenal atresia
- Hirschsprung’s disease
what type of genetic disorder is CF?
Autosomal recessive
What can CF cause
increased viscosity of secretions in the lung and pancreas
How are patients who have CF typically picked up? (3)
early in life due to failure to thrive or at birth via screening or failure to pass meconium
What is there a defect in in CF?
CFTR (cystic fibrosis transmembrane conductance regulator) which codes c-AMP regulated chloride channels.
What does the defective channel mean in CF?
excretes less chloride into the airway lumen and has a 3x increase in sodium absorption and water follows sodium
What are the pulmonary features of CF
recurrent chest infections in childhood -> early onset bronchesctasis.
later = resp failure, clubbing, cor pulmonale
What are the pancreatic features of CF?
steatorrhoea,
malnutrition and deficiniency of soluble minerals (A,D,E,K)
diabetes
What are the other features of CF?
failure to pass meconium at birth male inferitility (absent vas deferens) and female gall stones, cirrhosis, peptic ulcer, rectal prolapse and nasal polyps
What is the salt content like in CF?
it is increased.
What is the gold standard investigation in CF?
sweat test (>60 mmol/L)
What can early CXR identify in CF?
upper lobe bronchiectasis which will become diffuse later
What will lung function tests reveal in CF?
airflow obstruction with increased residual volume
What are common organisms that can colonise in CF patients? (4)
- Staph aureus
- Pseudomonas aeruginosa
- Burkholderia capecia
- Aspergillus
What is the management for CF patients? (6)
regular at least twice daily chest physio and postural drainage and deep breathing excercises.
prophylactic flucloxacillin for staph infections
high calorie diet with high fat intake
vitmain supplementation
pancreating enzyme supplementation
heart and lung transplant
What can open NTDs be defined as?
involve the entire CNS and neural tissue is expsoed with associated leakage of CSF
