Block 2 Week 6

Front 1

most common cause of thymic aplasia?

Back 1

DiGeorge Syndrome

Front 2

1-Alpha hydroxylase
-Function
-Location

Back 2

is located in the proximal tubule
hydroxylation of calcidiol to calcitriol (the bioactive form of Vitamin D)
(25 Vit-D to 1,25 Vit-D)

Front 3

Diagnostic testing

Back 3

is performed to identify a specific genetic condition in an individual based on his family history and clinical symptoms so A is correct.

-Used to confirm a diagnosis when a particular condition is suspected based on physical mutations and symptoms.

Front 4

Predictive testing

Back 4

Predictive and presymptomatic types of testing are used to detect gene mutations associated with disorders that appear after birth, often later in life. These tests can be helpful to people who have a family member with a genetic disorder, but who have no features of the disorder themselves at the time of testing. Predictive testing can identify mutations that increase a person's chances of developing disorders with a genetic basis,

Front 5

Pharmacogenomics
-Helps with what?

Back 5

Pharmacogenomics is a form of genetic testing that determines a patient’s genotype at genes involved in drug metabolism to estimate the probability a patient is a “slow metabolizer” or a “fast metabolizer”. Often these genes are in the P450 cytochrome oxidase pathway.
-Helps the physician decide the dose

Front 6

Chloride skin sweat test
-type of test?
-why

Back 6

a screening, rather than a diagnostic, test for Cystic Fibrosis. This is because there are other possible causes for high levels of chloride in newborn sweat. For those babies who screen positive by sweat test, the diagnostic test would be identifying mutations in the CFTR gene by DNA analysis (perhaps by DNA sequencing).

Front 7

Phenylketonuria (PKU)

Back 7

- an autosomal recessive metabolic genetic disorder
-necessary to metabolize the amino acid phenylalanine (Phe) to the amino acid tyrosine. When PAH activity is reduced, phenylalanine accumulates and is converted into phenylpyruvate (also known as phenylketone), which is detected in the urine
-Untreated PKU can lead to mental retardation, seizures, and other serious medical problems

Front 8

Digeorge syndrome
-etiology
-symptoms

Back 8

CATCH-22 3MB micro deletion 22q11.2

Cardiac Abnormality (especially tetralogy of Fallot)

Abnormal facies

Thymic aplasia

Cleft palate

Hypocalcemia/Hypoparathyroidism

Front 9

Huntington's disease (HD)

Back 9

-neurodegenerative genetic disorder that affects muscle coordination and leads to cognitive decline and psychiatric problems. It typically becomes noticeable in mid-adult life. HD is the most common genetic cause of abnormal involuntary writhing movements called chorea,
-autosomal dominant mutation in either of an individual's two copies of a gene called Huntingtin

Front 10

pleiotropy

Back 10

a single gene defect causing a complex of unrelated phenotypic effects

Front 11

Fragile X syndrome

Back 11

genetic disorder which occurs as a result of a mutation of the fragile X mental retardation 1 (FMR1) gene on the X chromosome, most commonly an increase in the number of CGG trinucleotide repeats
- condition with variable expressivity and possibly reduced penetrance.[20] It does not follow the usual pattern of inheritance for an X linked condition.

Front 12

When Estimating Allele Frequencies (inheritance risk) for an Individual, use what?
-what 2 paths can be taken

Back 12

Both the Family History and their Ethnicity

-If there is no history of the disease in the family, use population incidence, ethnic incidence or geographic incidence

-If family history is positive
examine pedigree for possible inheritance pattern(s)

Front 13

Challenges in Determining Inheritance Pattern?

Back 13

Semi-dominant
New “de novo” mutations
Variable Expressivity
Incomplete Penetrance
Pseudoautosomal inheritance
Pseudo-dominant
Sex-limited

Front 14

80% of patients with Achondroplasia have unaffected parents
-Why is this unusual
-How does this happen

Back 14

Achondroplasia is caused by a dominant mutation, and is semi-dominant (phenotype of heterzygotes)
-a dominant mutation can arise as a “new mutation” in a parental gamete and then be transmitted to offspring

Front 15

Neurofibromatosis Type 1 (NF1)
-type of inheritance?

Back 15

Autosomal Dominant withVariable Expressivity
-a person’s phenotype may vary from mild to severe, but it is never absent

Front 16

incompletely penetrant.

Back 16

Individuals with a genotype known to cause a phenotype may not have that phenotype

-Autosomal dominant (HNPCC), only 80% of persons who carry a mutant HNPCC allele will develop cancer during their lifetime.

Front 17

Pseudoautosomal Inheritance

Back 17

Pseudoautosomal region of Y and X undergoes pairing and recombination during meiosis

-SHOX gene “Short stature homeobox”

Front 18

A Pseudo-dominant disease

Back 18

Inherited in an Autosomal Recessive pattern with incomplete penetrance BUT --> Mimics Autosomal Dominance

Front 19

consanguinity

Back 19

For rare autosomal recessive phenotypes, parents of affected children often share a common ancestor

Front 20

PKU inheritance pattern?

Back 20

PKU, an autosomal recessive genetic disease
-PKU is a fully penetrant disorder

Front 21

Recurrence risk

Back 21

The likelihood that a trait or disorder present in one family member will occur again in other family members in the same or subsequent generations

Front 22

Why is menstruation similar to parturition?

Back 22

Both are due to a dec in progesterone responsiveness, both have contractions of the uterus (in menstruation progesterone drops, in parturition progesterone sensitivity drops)