Paediatric genetics Flashcards
Way to investigate child with learning difficulties?
look at the chromosomes (karyotype)
Down’s syndrome is associated with?
Learning disability Congenital heart disease Hypothyroidism Immunity Early onset Alzheimer disease
Pretnatal testing for downs syndrome
amniocentesis
free fetal DNA in maternal blood is no risk to fetus
what is trisomy 18?
Edward’s syndrome
Multiple congenital anomaly syndromes - what % are single gene disorders , chromosomal an teratogen?
30%
10%
5%
Multiple Congenital Anomaly Syndromes are individually rare but?
common with a group
how to diagnose a rare intellectual disability + / or malformation syndrome
- give examples of the testing used?
History Description Recognition of patterns Testing Standard- biochemical, chromosome structure Microarray now standard Targetted testing Moving to trio-based exome / genome
How do we describe a Dysmorphic Child? (4)
Position and shape of facial features
Hands
Growth of child
General features
what to look for in the head?
Shape
Size: macrocephaly, microcephaly
Ear position
Low set, posteriorly rotated indicates lack of maturity
Abnormalities of the eyes - what is Hypertelorism
Inner canthal distance ICD and inter-pupillary distance IPD increased (eyes are too far form each other)
Abnormalities of the eyes - Telecanthus / epicanthic folds
the measurement between the eyes in increased
- Down’s syndrome
what is telecanthi?
there are folds at the eyes
what do we look at with hand measurements?
Finger length
Digital abnormalities
Palmar creases (normal 2)
1 palmar crease can be seen in?
Down’s syndrome
Marfan’s syndrome features
long fingers
- the MF/THL >44%