exam 2 review Flashcards
exam 2
Turner syndrome usually ends in
miscarriage
most common autosomal aneuploidy leading to miscarriage
Trisomy 16
Scalp defects (cutis aplasia), microcephaly, micropthalmia, holosencephaly, cleft lip, and palate
- renal anomalies
- polydactyly
- CHD
Patau
small size, microcephaly, congenital heart defects, overlapping fingers, rocker bottom feet
Edwards
Flat facial profile, upslanted palebral fissures, anomalous ears, nuchal ckin fold, single palmar crease, clinodactyly, hypotonia, hyperflexibility of joints
Down syndrome: newborn features s
Lymphedema in infancy, bicuspid aortic valve, coarctation of aorta, short stature, gonadal regression, horseshoe kidney, cubitus valgus elbow, low posterior hairline, webbed neck, widely-spaced hypoplastic nipples
turner syndrome
tall- statrue, long limbs, learning disability, gynecomastia, small testicles, infertility due to hypogonadism w/ oligospermia/azoospermia
Klinefelter
47, XXY
Klinefelter
45, X
turner
47, xx+21
trisomy 21- down
47,XX+18
trisomy 18- edwards
47,xx+13
trisomy+13
M1 Block
heterodisomy
M2 block
isodisomy
loss of material
deletion
gain of material
duplication
alteration w/in a chromosome
inversion
exchange of material between two or more chromosome
translocation
hypotonia, intellectual disability, hyperphagia (pathological eating)
Prader-willi
lack of paternal allele expression
Prader-Willi
severe intellectual disability, movement disorder, seizures
angelman
lack of expression of maternal allele
angleman
robertsonian translocations chromosomes
13,14,15,21,22
results in loss of non-critical genes in the short arm regions of the chromosomes involved
robertsonian translocations
46,xy,t(1;8)(p22;q24)
balanced
46,xx,der(8)t(1;8)(p22;q24)
unbalanced
45,xx,der(13;14)(q10;q10)
robertsonian
used to confirm clinical dx such as:
- trisomy 21
- large changes
- balanced translocations
karyotype analysis
use for quick answer to specific questions:
- microdeletion syndrome
- recurrent acquired translocations
- recurrent acquired numerical changes
FISH analysis
a single nucleotide base changed
point mutations
replace one aa with another
missense mutation
properties of an aa remain the same
conservative
properties of the aa are different
non-conservative
create a premature stop codon
non-sense mutations
same aa produced despite difference in DNA sequence
silent mutations
absence of a portion of DNA sequence (usually in coding DNA or regulatory sequences)
Deletions
large deletions often result in the loss of multiple _______ genes
contiguous
In deletions, size can vary ____ base pair to millions of base pairs and possibly less damaging if in multiples ____bp
In deletions, size can vary 1 base pair to millions of base pairs and possibly less damaging if in multiples 3 bp
a constellation of findings due to a specific deletion that encompasses several genes
microdeletion
microdeletion is not visible in
karyotype