Genetic Disorders
Autosomal Dominant & Recessive Disorders
Mitochondrial DNA Disorders & Multifactorial Inheritance
X-Linked Disorders
Chromosomal Disorders
100

a single gene variant that alters protein or decreases protein/enzyme productions

what is single-gene disorder?

100

one copy of a gene causes disease. it's a mutation of extracellular matrix protein abundant in connective tissue. Clinical manifestations include skeletal abnormalities (long arms & fingers + hyper-extensible joints), vision problems, and cardiovascular complications (floppy valves)

what is Marfan Syndrome ?

100

contain DNA that is distant from DNA in nucleus 

what is mitochondria DNA (mtDNA)? 

100

homozygous (both Xs have trait) to show phenotype. If heterozygous for trait, will RARELY have phenotype  

what are XX persons with recessive disorders ? 

100

structural abnormalities where chromosome breaks into pieces then rearranges of parts are deleted.

what is chromosomal disorder?

200

Tay-Sachs, Cystic Fibrosis, & Sickle Cell Anemia 

What are single gene disorders? 
200

genetic defect in tumor suppressor gene and causes tumors to develop in the nervous system. There are 2 types: von Recklinghausen disease (in peripheral nerves) & bilteral acoustic (Shwann cell tumors; less common; symptoms headache, hearing loss, tinnitus) 

what is neurofibromatosis?

200

these disorders are not common and often cuase problems in tissues with high metabolic needs (i.e. muscle & nervous) 

what are mitochondrial DNA disorders (mtDNA) disorders? 

200

Only has one X chromosome, so all XY people affected. Also occurs in X0 persons

What is XY recessive disorder?
200
change in chromosome number of autosomes (e.g. Down Syndrome/Trisomy 21)

what is numeric autosomal chromosomal disorder?

300

cutaneous + subcutaneous neurofibromas that develop late in childhood or adolescence as well as cafe au lait spots (large, flat pigmentations)

what are clinical manifestations of Neurofibromatosis? 

300

Diabetes, cardiovascular disease, cancer. 

what are disorders that manifest due to environmental influences? 

300

XX offspring have 50% chance of being carrier. XY offspring has 50% chance of having disease. An affected XY person will give X gene to ALL XX offspring.

what is parent is a XX carrier?

300

Error in meiotic cell division. This is the most common chromosomal disorder. Manifestations include: intellectual disability, physical characteristics, & congenital heart defects. Increased risk of lymphoblastic leukemia & GI malformations.

what is Trisomy 21/Down Syndrome? 

400

metabolic disorder where elevated phenylalanine levels are toxic to the brain. Deficiency in liver enzyme (PAH) that converts phenylalanine to tyrosine. Source is protein rich foods and we only use a little and convert the rest. Fasting, starvation triggers muscle catabolism = increased levels. This is screened in birth and if left untreated = will cause intellectual impairment & impaired neurologic development  

what is Phenylketonuria? 
400

mutant X* chromosome is dominant to normal X. Will be affected. Affected heterozygous persons (X*X) has a 50 % chance to transmit the mutant X* chromosome to offspring. X*Y persons will have 100% affected XX offspring (all will be affected) and 100% unaffected X*Y offspring (if other parent doesn't have mutated X chromosome).

what is X-linked dominant disorders? 

400

Absence if all (45 chromosomes, X0) or part of X chromosome. Clinical features include: short stature, ovarian dysgenesis, cardiac abnormalities. Can be treated with growth hormone and estrogen therapy. 

what is Turner Syndrome?

500

Lysosomal storage disorder due to lack of hydrolytic enzyme leading to increases sphingolipids in nervous tissue (brain). This leads to destruction of neurons which leads to gradual deterioration of motor & mental function. This is fatal at 4-5 years of age. 

what is Tay-Sachs?

500

This is the most common form of inherited intellectual disability X-linked dominant disorder. Affected males (X*Y) are more severe than  affected females (X*X)

what is Fragile X syndrome?

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