mendelian inheritance Flashcards
genotype
particular combination of alleles for a particular gene or loci
heterozygous
both alleles different
homozygous
both alleles same
phenotype
observable characteristics as a result of the genotype
appearance, development and behaviour
penetrance
proportion of people in population with the genes and express the trait
variable expressivity
range of signs and symptoms expressed in people with same genetic condition
consanguinity
married 1st/2nd cousin or closer
obligate carriers
might not be clinically affected, but pass it on
genogram
pictoral display of a person’s family realtionships and medical history
created with simple symbols showing the gender and status
lines show familial relationshoip
where in practice are genograms used
GP, oncology, paeds, clinical genetics
diamond
gender unknown
number in shape
multiple indivinduals
n in shape
multiple individuals - number unknown
line through
deceased
line through and SB
still birth - gestation
P in shape
pregnancy (LMP below) or gestation
P and arrow towards shape
proband
just arrow toward shape
consultand
triangle
sponateneous abortion (shaded = affected spontaneous abortion)
termination of pregnancy
triangle with line through
horizontal line
mating
horizontal line with parallel lines
relationship no longer exits
question mark to child
biological parents unknown
one line from parents that spilts
twins
(with joining line - MZ)
with qn mark - zygosity unknown
horizontal line instead of cjhild line
no children
parallel lines horizontal instead of where child should be
infertility
dashed line to child and sq brackets around
adoption in
solid line to child and sq brackets
adoption out
proband
starting point for study of family
1st affected family member who seeks medical attention
consultand
a person whose future offspring the genetic counsellor is to make predictions about
