Genetics 2 Flashcards
May be markers for diabetes or hypertension
single nucleotide polymorphism
Fragile X syndrome is an example
trinucleotide repeat mutation
sickle cell anemia is an example
point mutation
Huntington disease and neurofibromatosis is an example of
autosomal dominant disorders
Oral-Facial-Digital syndrome (OFD) type I is an example of
X-linked dominant
Autosomal dominant disorder of CT due to mutation of “FBN1 gene” –> you get abnormal “fibrillin” (which is a glycoprotein necessary for normal elastic fiber production
Marfan syndrome
Tall, thin body with abnormally long legs, arms, and fingers (Wolters….)
Dislocation of the eyes
Aortic aneurysm and dissection leading to heart failure and aortic rupture
Marfan syndrome
collagen synthesis problem
ehlers-danlos syndrome
This causes:
xanthomas of the skin
premature atherosclerosis - plaque build-up in arteries
hypercholesterolemia
Mutation in the gene for the LDL receptor resulting in impaired metabolism and increased LDL cholesterol in plasma
hypercholesterolemia
-normal at birth, but within 6 months elevated phenylalanine levels impair brain development and mental retardation is evident
Phenylketonuria
-Screening at birth is mandatory in USA and restricting dietary phenylalanine intake will prevent mental retardation
Phenylketonuria
-accumulation of insoluble large molecules in macrophanges with hepatosplenomegaly
Lysosomal Storage Diseases
frequent CNS involvement, mental retardation, and/or early death
Lysosomal Storage Diseases
-associated with increased maternal age
45 years old - 1:25
Trisomy 21 aka Down Syndrome:
you get increased susceptibility to infection like periodontal disease in childhood
Trisomy 21 aka Down Syndrome:
large tongue and epicanthic folds
Trisomy 21 aka Down Syndrome:
this occurs due to meiotic non-disjunction of chromosome 21 during formation of the ovum
Trisomy 21 aka Down Syndrome:
defined as male hypogonadism that develops when there are 2 chromosomes and one or more Y chromosomes
Klinefelter Syndrome
increased length of lower limbs, reduced body hair, gynecomastia - most common reason for hypogonadism (swelling of breasts in males)
Klinefelter Syndrome
short stature, webbed neck, low post hairline, high-arched palate. primary amenorrhea (absence of menstruation)
Turner Syndrome
due to partial or complete absence of the X chromosomes
Turner Syndrome
used fliorescent dye-labeled probes that recognize sequences specific to chromosomal regions
fluorescence in situ hybridization
uses different colored dyes attached to large segments of the test DNA and normal DNA, followed by hybridization
comparative genomic hybridization
- PCR analysis - amplify the DNA in question
- compare the order of nucleotides of this DNA to a normal DNA sequence
- use restriction enzymes and run the segments on gel electrophoresis, compare to normal DNA
molecular diagnosis of genetic disorders
