family trees Flashcards
start with informant
make sure you have enough space
do close family 1st then extended
write informants name, DOB and medical info
male partner should be on the L
determine if consanguineous - see if surnames the same before marriage
ask about children
ask draw 1st on L LMP - last menstrual period EDD - expected date of delivery miscarriages - ask number of weeks, see if reason for termination
ask about siblings
see how many
if died
how many children have they had
did they lose any children
record details of parents
DOB
medical conditions
siblings if necessary for purpose
collect info of partner
and their family
additional qns
where grandparents from - some conditions more common in different locations, or small gene pool = more consanguinity
is there something else I should know
final steps
date
name
key
ask consent to share
autosomal dominant trait
one that manifests in the heterozygous state
can trace through the family
chance of child inheriting a dominant allele from a person affected
50%
pleiotropy
single gene may give rise to 2 or more unrelated effects
example of pleiotropy
phenylketonuria
inborn error of AA metabolism
reduced or absent phenylalanine hydroxylase
normally converts phenylalanine to tyrosine
high levels phenylalanine = nervosu system toxicity , blond hair and blue eyes, musty odour
tyrosine
precursor to catecholamine, neurotransmitter, melanin formation
variable expressivity
eg AD polycystic kidney disease - some affected individuals develop renal failure early, some only have a few cysts
reduced/incomplete penetrance
some people with mutation don’t develop features
co-dominance
2 allele traits expressed in heterozygous state
eg blood groups
