LECTURE IX Flashcards
50% of genes in common
parents, dizygotic, or siblings and children
first degree relatives
25% of genes in common
grandparents, aunts, uncles, nephews, nieces, and grandchildren
second degree relatives
12.5% of genes in common
great grandparents, great grand children, first cousin
third degree relatives
100% of genes in common
monozygotic twins
a trait whose expression varies gradually between extremes
continuous trait
a feature which at one extreme of expression manifests as a disorder
quasi continuous trait
height, weight, intelligence, total ridge count, RBCs, blood pressure, skin colour
are examples of continuous or quasi continuous trait?
continuous trait
sex influenced trait 2:1 M:F
both genetic and environmental etiology
bilateral in 50% of cases
often the orthopedic deformities or neurologic defects
talipes equinovarus or club foot
trisomy 21 is what disease?
Down syndrome phenotype
45XO is what disease?
Turner syndrome phenotype female
5p (del) is what syndrome?
Cri-du-chat syndrome
what are the types of chromosomal abnormalities?
constitutional vs acquired
homogenous vs mosaic
numerical vs structural
what type of chromosomal abnormalities is this:
all cells have it from the time point zero
constitutional
what type of chromosomal abnormalities is this:
some cells have the chromosomal abnormality and so once this carries over to organ development it carries on in that lineage of cells
acquired
what type of chromosomal abnormalities is this:
karyotyped cells have this chromosomal abnormality
homogenous
what type of chromosomal abnormalities is this:
only a portion of chromosome have triploid vs normal diploid of chromosomes
mosaic
what type of chromosomal abnormalities is this:
unbalanced chromosomal abnormality
numerical
what type of chromosomal abnormalities is this:
more or less than that amount
structural
what type of rearrangement is this?
individual still has full complement in cells
may not be abnormal phenotype in individual
often identified in offspring
balanced rearrangements-balanced carrier
what type of rearrangement is this?
phenotype likely to be abnormal due to a deletion or duplication
often produces abnormal fetus
duplications are comparable to a partial trisomy so,
deletion to a partial monosomy
unbalanced rearrangements
name this type of structural abnormality?
involves the exchange of segments from two nonhomologous chromosomes
non homologous reciprocal translocations
name this type of structural abnormality?
occur when part of a chromosome is missing, a part of a chromosome is extra, or a part has switched places with another part
deletions
name this type of structural abnormality?
if the chromosome splits transversely rather than longitudinal
isochromosomes
name this type of structural abnormality?
this can happen across the centromere or within the same arm, name two specific types
pericentric and paracentric inversions
name this type of structural abnormality?
a major mechanism through which new genetic material is generated during molecular evolution. … Common sources of gene duplications include ectopic recombination, retrotransposition event, aneuploidy, polyploidy, and replication slippage.
duplication
name this type of structural abnormality?
an aberrant chromosome whose ends have fused together to form a ring.
ring formation
