Dysmorphology and Bioinformatics Flashcards
What is dysmorphology?
The study of congenital malformations (birth defects).
-particularly anatomy related
What proportion of births have congenital malformations?
2-3%.
What congenital malformations are more likely to be genetic?
- Dysmorphic
- Multiple malformations
- FH
What is ectrodactyly?
Split / cleft hand.
What is Waardenburg syndrome?
Autosomal dominant condition.
|»_space; deaf, cleft lip, iris heterochromia, premature greying
What is Pallister-Killian syndrome?
Tetrasomy 12p mosaicism.
|»_space; developmental delay, hypotonia
What does 22q11.2 deletion lead to?
DiGeorge syndrome.
- learning difficulties
- cleft palate
- congenital heart defect
- seizures
What is achondroplasia?
Form of dwarfism.
- short limbs (Rhizomelic), hydrocephalus, large head
- autosomal dominant inheritance
What increases the risk of achondroplasia?
Increased paternal age.
What are the features of Beckwith-Weidemann syndrome?
- Large tongue
- Ear creases
- Exomphalos
- Hemihypertrophy
- Increased Wilms tumour risk
What does a single palmar crease indicate?
Down syndrome.
-however, 4% (unilateral) / 1% (bilateral) of the population have it
What is Down syndrome associated with?
Learning difficulties Congenital heart disease Cataracts Hypothyroidism Leukaemia
What are the main features of Kabuki syndrome?
Learning difficulties
Congenital heart disease
Poor growth
Cleft palate
What condition is associated with persistent foetal finger pads (96%)?
Kabuki syndrome.
What condition is associated with GI polyps and malignancies (colorectal, gastric, breast, ovarian)?
Peutz-Jeghers syndrome.
What is Treacher-Collins syndrome?
Autosomal dominant.
-very variable; cleft palate, hearing impairment
What genetic abnormality leads to William’s syndrome?
7q11 deletion.
What are the main features of William’s syndrome?
Learning difficulties
‘Cocktail party’ speech
Congenital heart defect
Hypercalcaemia
What is Gestalt diagnosis?
Making a diagnosis based on a few signs.
-e.g. physical features at birth
What is bioinformatics?
Applying computer technology to management of biological information.
Where should you get information from for bioinformatics?
The internet.
-textbooks are out of date
What are useful bioinformatics resources? (4)
- OMIM (genes, mode of inheritance)
- GeneReviews (prevalence, diagnosis)
- Orphanet
- GARD
What website is commonly used for genetic diagnosis?
UK genetic testing network (UKGTN).
What information do array CGH results contain?
- Chromosomal imbalances
- Copy number variation
- Gene duplication / deletion
What is Cockayne syndrome?
Autosomal recessive.
|»_space; decreased growth, premature aging, microcephaly, impaired NS development
