Introduction to chromosome disorders Flashcards
1
Q
Why diagnose?
A
Helps to have a name Prognosis Associated problems Genetic counselling Prevent unnecessary investigations Possible treatment
2
Q
Dysmorphology consultation
A
History: pregnancy, birth, development, problems
Family history, consanguinity
Physical examination
Examine parents and sibs if necessary
3
Q
Difficulties with Dysmorphology diagnosis
A
Syndromes extremely variables sometimes Maybe rare or unique to family One syndrome can be caused by multiple genes (heterogeneity) One gene can cause different syndromes Features may develop over time
4
Q
What is a syndrome?
A
A non random association of multiple malformations or alterations in body form that are pathogenically related
5
Q
Indications for chromosome analysis
A
Developmental delay Learning difficulties IUGR or failure to thrive Microcephaly Facial dysmorphism Multiple congenital malformations
6
Q
Kabuki syndrome
A
Developmental delay Long palpebral fissures Everted lateral lower lid Arched eyebrows Broad nasal tip Large ears, prominent lobes High palate Short stature Renal anomalies
7
Q
Chromosomal abnormalities
A
Polyploidy Autosomal trisomies Sex Chr abnormalities Del/dup Inversions Ring Chr Translocations (Robertsonian) Mosaicism UPD
8
Q
Down syndrome
A
Up slanting palpebral fissures Epicanthic folds Brachydactyly Small simple ears Large tongue Single palmar crease Mid face hypoplasia
1 in 750 births
Risk increases with advanced maternal age
