Questions asked Flashcards
complete dominance
where a dominant allele completely masks the effect of a recessive allele
chorionic villus sampling
form of prenatal diagnosis
cells are removed from the placenta
in a non-DS individual how many chromosomes result from a Robertsonian translocation t(14q:21q)
45
eg. chr14 and 21 fuse so there is one less than the normal diploid
in a DS pt, how many chromosomes result from a Robertsonian translocation t(21q:21q)
46
as there is an extra chr21
so two fuse=45
but the extra chr21 means +1 = 46
dignostic testing definition
confirmation of a clinical impression
karyotype definition
a photograph of chromosomes
arranged in a standard way
what is haploinsufficiency
one copy of a gene is inactivated/deleted
and the remaining functional copy does not produce enough for the wild type condition