MI Unit 2 Review

Case 1

Case 1

Huntington's DIsease It is a genetic disorder that causes the breakdown of nerve cells within the brain Begin to develop when you are older Caused by a mutation in the huntington gene that causes a protein to be longer than it usually is and this protein helps with the development of the brain Stages of huntington's disease

1. Mostly functional (can last 8 years) 2. Less functional, but can carry out their daily life with mild difficulty 3. Patient can no longer work and needs substantial help from a caregiver. Their cognitive and motor functions symptoms 4. A patient is no longer independent. They know what they need to get done, but it requires assistance 5. Needs substantial assistance. Motor and psychiatric worsen and parkinson's can occur The patient and her father have been diagnosed with Huntington's disease Tonya (the patient) has shown no symptoms and is wondering if she should have her kids tested yet Symptoms: chorea, difficulty balancing and swallowing, inability to process thoughts, depression, insomnia, fatigue, and impulsiveness Treatments: therapy, antidepressants, sleeping pills, and vestibular suppressants Types of therapy: physiotherapy: helps with motor issues, psychotherapy: treating more severe depression, insomnia etc Doctors: Neuropsychiatrists, neuropsychologists, social workers, neurologists Organizations for help: The Huntington's Disease Society of America and The International Huntington Association Unfortunately it is incurable and fatal For her children, HD is a genetic dominant genetic disorder Have Tonya's partner to get genetically tested Advice: wait about ten years and ask their children if they want to be tested because it is their choice to make

Resolution: I would have my partner get genetically tested for Huntington's if I were Tonya. Also, I would wait longer for the kid's to be genetically tested because it should be their choice if they want to know or not.

Case 2

Fragile X (should be memorized) Resolution: I would try to get Alvin on some medications to control his anxiety. I would also have him go to behavior, speach, and occupational therapy so that he can better his life.

Case 3

Marfan's disease Affects someone's connective tissue Most inherit it from their parents Symptoms: tall and skinny, long limbs, heart murmurs, abnormally curved spine, and flat feet Each child with an affected parent have a 50% chance of inheriting the gene Prognose: life expectancy is 70 years, possible eye problems, possible bone problems, cardiomyopathy (when the heart struggles to deliver blood to the rest of the body), or arrhythmia (irregular heartbeat) You can live a fairly normal life style Juliet should stop playing basketball due to its contact

Resolution: I would not do basketball if I were Juliet. The bone and heart issues would not combat well for playing a contact sport, but I would still play with my friends or do lighthearted pick up games.

Case 4

Phenylketonuria (PKU) A recessive single gene genetic disorder It causes excessive buildup of amino acid phenylalanine (phe) due t the mutation of the gene for a certain enzyme that converts (phe) to tyrosine which is important for neurotransmitters of the neurons in the brain low levels of Tyr result from PKU due to the being broken down symptoms symptoms: neurological problems, pale skin and blue eyes, hyperactivity, eczema, intellectual disability, behavioral, emotional, psychiatric, and social problems prognosis if left untreated: irreversible brain damage, seizures, tremors, major developmental problems tis heavily concentrated on the brain One can be put in a PKU diet that includes eating foods low in protein PKU formula: nutritional supplement that contains essential proteins and doesn't have Phe in it Neutral amino acid therapy: supplement in powder or tablet form that block some of the absorption of Phe PKU medication: drug called sapropterin helps bui;d tolerance to Phe and is used in conjunction with the PKU diet Phe is needed to a certain extent, but the point is to have ONLY what is necessary and nothing more Chang family - they have a daughter and a newborn named jennifer who has the disease What to avoid: foods high in protein Keeping with the modern day treatments, people with PKU live into their adult years. Recommendations: Put jenifer on the pku diet for newborns right away 25% chance that another child they will have will have PKU do genetic testing start treatments early go on the medication tis a recessive disorder

Resolution: If I were in the Chang family, I would Jennifer on a PKU diet. This way she will know how to accommodate for her disorder in a healthy way.

Case 6

Leukemia Affect white blood cells and causes abnormal white blood cells to form Treatments: chemotherapy, radiation therapy, umbilical cord transplant, or a bone marrow transplant The family needs bone marrow in order to save the child There are some genetic factors don't cause leukemia for the most part It is mostly caused by environmental factors Patrice most likely has ALL or AML leukemia due to the genetic factors Her cancer could be caused by both genetic and environmental factors The bone marrow transplant is risky, and if the parents were to have another kid there is only a 75% chance that the bone marrow would match Advice: check the bone marrow registry first for a transplant, get genetic testing done

Resolution: If I were in the Thompson family, I would wait a little bit longer to find a bone marrow match. I would not jump to having another baby because there is a 75% chance that the baby's bone marrow would not match Patrice's. However, if they had been planning to have a second child before finding out about Patrice's leukemia, then I would say they should go for the baby option because they would have the family they want plus a possible bone marrow match. Yet, I would not go for the baby option if the sole purpose would just be to save their first child.

Case 7

Schizophrenia A disorder where a person's ability to think, feel, and behave Symptoms include: delusions, hallucinations, disorganized thinking Neurotransmitters are either not active or too active There are large spaces in the brain, parts of the brain that deal with memory, fewer connections between brain cells Areas of the brain that run on dopamine, the brain chemical dopamine tied to hallucinations and delusions become overactive In hallucinations, you see something that you think is real, but in delusions you think something and you believe it if your parent has s, you have a 10% chance increase of getting it There is no cure, only medication and behavioral therapy You typically do not develop s until you are 45 she should monitor her health to see if there is a decline in her mental health There is no genetic test for it Make sure there is no alcohol or drug abuse

Resolution: If I was Jane, I would closely monitor my health and get years mri's specifically when I'm older to look out for signs of schizophrenia. Since there is no genetic test, I would try my best to research symptoms and learn more about the evolution of the disease.

Case 8

Polycystic kidney disease (PKD) It is an inherited disorder in which clusters of cysts develop in the kidneys If these cysts become large, the reduced kidney function and lead to failure Symptoms: pain in areas of back, fatigue, high blood pressure, blood in urine, or lump in the abdomen Treatment: medications to control blood pressure, pain relievers cyst removal, kidney transplant, ACE inhibitor (medication that widens your blood vessels) aka increases the amount of blood your heart pumps and lowers blood pressure There is dominant and recessive D: develop between 30 and 40 (the type john has), symptoms get worse over time. This one is genetic R: affects more children because it is genetic and sporadic in a baby. This makes the kidneys enlarged 90% of cases are dominant and 10% are recessive Hereditary D: only one parents needs to have it to pass the disease onto their children In john and marta's case, their child has a 50% chance of getting the disease Genetic testing: use a sample of white blood cells or cells from other tissues To test an unborn child, cells from the placenta or amniotic fluid can be tested In John's situation, they should test the child asap A large kidney can put pressure on the child's lungs and affect their breathing recommendation: get a genetic test asap, take blood pressure medications, watch diet for salts, regular exercise, and limit alcohol use

Resolution: If I were John, I would test their baby because there are tests for unborn babies. This way they can know before the baby is born. I would also take blood pressure medications, watch diet for salts, and regularly exercise use for my own safety.

Case 9

Prader-Willi syndrome A child might have downs syndrome, but they actually have PWS It is a disorder that causes numerous mental, physical, and behavioral issues Causes issues in the hypothalamus It is caused by a deletion of a part of chromosome 15 It is mainly caused by the father Symptoms: a feeling of never being full, little to no production of sex hormones, delayed or lack of menstrual cycles Super rare that this is inherited by the mother, so it is tracked through the males 25% a child will inherit this disorder The excess weight would cause issues that lead to diabetes, high blood pressure, etc. So, the disease isn't fatal, but it can lead to things that lead to fatal diseases How to deal with a child that has this help their nutrition and diet (a diet high in calories), growth and sex hormone treatments to produce the correct hormones, therapists and people that can help the child and family, and a neurologist bc there are hypothalamus issues

Resolution: If I were a part of the Cruz family, I would try not to discount having more children. There is a 25% chance that one of their children will get PWS, so they can still have other children. However, I would recommend seeing a genetic counselor to get a full view of things for their future children and not having a large family. I also would help Luisa's nutrition and diet (a diet high in calories), give growth and sex hormone treatments to produce the correct hormones, and have therapists and other medical professionals to help the Luisa and family.

Case 11

Kearns-Sayre Syndrome Florence has five kids She has healthy parents with no sign of the disease Ways to know if it will affect her children Rare neuromuscular disorder that is onset before the age of 20 years Cased by abnormalities in mitochondrial DNA Incurable There is vision impairment as well It affect the nervous system, the heart, can lead to diabetes, seizures, tremors All due to the lack of energy from the mitochondria Although KS is not fatal it can lead to fatal results It is rarely inherited and occurs after conception Always transmitted from the mother because all mdna is from the mothers Her children would be at risk, but low risk If her daughter's have children then they would also be at risk because it is a maternal pathway Advice: inform the daughters, tell them the low-chance, keep an eye out for symptoms

Resolution: If I were Florence, I would inform my daughters about KSS, tell them they have a low-chance of getting it, but they can give it to their children, and try to keep an eye out for symptoms because it's usually onset before the age of 20.

Case 13

Hemophilia A rare disorder that leads to uncontrollable bleeding This is caused by a lack of clotting factors in the blood the disease is genetic and cause by a mutation or absence of the clotting factors which is a gene This is a recessive x-linked disorder (similar to fragile x) Genetic testing for this can be done through a blood test or a search for an inversion Symptoms: uncontrollable bleeding, spontaneous bleeding, prolonged bleeding More general symptoms: nose bleeds, blood in urine, joint pain or swelling, headaches, internal bleeding (mainly in the joints) Treatment: avoid strain on joints, prophylaxis decreases risk of internal bleeding, replacement therapy (replacing the missing clotting factors), a liver transplant (only long-lasting solution, but it isn't foolproof) Prognosis: a little bit of a shorter life-expectancy, without proper treatment people really cannot live into adulthood, more prone to heart disease,liver disease, and so on It can be mild, moderate, or severe There is A and B depending on which gene is affected No cures, but treatment methods can be very successful

Resolution: If I were Maria, I wouldn't consider having a baby until Ron gets tested first. Then as a group, we could determine the percentage that the child has of inheriting the disease. If the chance was very low, I might consider having another child. And if it was high, I would not consider having another child.

maternal serum screening 1st trimester

tests plasma for PAPP-A and hCG

NT ultrasound 1st trimester

looks for fluid behind the nape of the neck, the higher the fluid the higher the risk of chromosomal abnormality

quad panel maternal serum screening 2nd trimester tests for

AFP, hCG, UE3, DIA

AFP

alpha-fetoprotein, rise until week 12 then slow decline til birth, increased leakage into amniotic fluid point to neural tube defects

hCG test results meaning

high number down syndrome, low number edwards syndrome

uE3 unconjugated estriol,

produced by fetus, form of estrogen, low # down syndrome

hCG roles in body

angiogenesis, differentiation, immunosuppressor, growth, uterine muscle contraction, organogenesis, umbellical cord

DIA dimer inhibin A

produced by placenta, rises- drops between 14-17- rises til birth, high # down syndrome

spina bifida test results

high AFP

downs syndrome test results

high HCG, low uE3, low AFP, high DIA

Edwards syndrome test results

low HCG, low UE3, high or low AFP, N/A DIA

anatomy ultrasound 2nd trimester

confirms pregnancy, fetal heart rate, gestational age, fetal size, diagnostic of fetal malformation, placenta location, multiple pregnancies, high/low levels of amniotic fluid, intra-uterine death, fetal movement, pelvic abnormality

fetal size tests measure

crown to rump, circumference of head, femur length abdominal circumference, diameter of amniotic size, diameter of yolk sac prior to week 5

non-invasive prenatal screening: cell-free fetal DNA analysis

early as 10 weeks, down syndrome/trisomy 18/trisomy 13/x and y chromosome

pre-natal vitamins

iron, vitamin D, calcium, vitamin A, iodine, zinc, sodium, potassium, magnesium, vitamin C, vitamin B1 (thyamine), B2, B3, B9 (folic acid), B12, vitamin E

amniocentesis

a technique for determining genetic abnormalities in a fetus by the presence of certain chemicals or defective fetal cells in the amniotic fluid, obtained by aspiration from a needle inserted into the uterus

anneal

to be capable of combining with complementary nucleic acid by a process of heating and cooling

carrier screening

indiscriminate examination of members of a population to detect heterozygotes for serious disorders, determines if someone have a particular recessive disease even though they do not show the train phenotypically

CVS

a technique for diagnosing genetic and congenital defects in a fetus by removing and analyzing a sample of the fetal portion of the placenta

denaturation

in DNA, the separation of the two stands of the double helix

gene

a discrete unit of hereditary information consisting of a specific nucleotide sequence of DNA

genetic counseling

a process of communication that deals with the occurrence or risk that a genetic disorder will occur in a family

genetic testing

the use of methods to determine if someone has a genetic disorder, will develop one, or is a carrier

genome

the complement of an organism's genes; an organisms genetic material

genotype

the genetic makeup of an organism

karyotype

a display of the chromosome pairs of a cell arranged by size and shape

newborn screening

the analysis of a neonate's blood for metabolic or genetic disorders to prevent mental retardation, disability or death

phenotype

the physical and physiological traits of an organism

polymerase chain reaction

technique that involves copying short pieces of DNA and then making millions of copies in a short period of time

preimplantation genetic diagnosis

in assisted reproductive technology, the determination of genetic abnormalities in the embryo before it is transferred to the uterus, single cell is removed from an embryo and examined for chromosome abnormalities or genetic changes, parents and doctors can then choose which embryos to implant

primer

a short piece of DNA or RNA that is complementary to a section of template strand and acts as an attachment and starting point for the synthesis strand during DNA replication

restriction enzyme

degradative enzyme that recognizes specific nucleotide sequences and cuts up DNA.

single nucleotide polymorphism

one base-pair variation in the genome sequence

supernatant

the (usually) clear liquid left behind after a precipitate has been spun down to the bottom of a vessel by centrifugation

taq polymerase

DNA synthesis enzyme that can withstand the high temperatures of PCR

thermal cycler

instrument that automatically cycles through different temperatures used to complete PCR reactions

ultrasonography

noninvasive technique involving the formation of a two-dimensional image used for the examination and measurement of internal body structures and the detection of bodily abnormalities

what information can an individual gain from genetic testing? why wouldn't everyone want their genes tested?

-if they are going to inherit a genetic disease or not -carrier or not -risk of passing to their kids -some don't want to live knowing their gonna get a disease that will kill them

what are the duties of a genetic counselor?

-determine if there is a genetic disease that runs in the family -make recommendations to patients -help them cope -explain options -what to expect/possible outcomes

describe the get testing process for an individual wanting to be screened for a genetic disease. include the molecular tools and their role.

-sample of blood, hair, skin, or nails, amniotic fluid, or other tissue are obtained -find gene of interest and amplify using PCR -DNA is compared to the human genome

what occurs during the three critical steps of the PCR process?

-denaturation, temperature is increased very high so the DNA will split -annealing, temperature is lowered and primers are added, primers attach to specific sequences of the DNA extension, polymerase is added to copy and extend the DNA -thermocycler is used to control the temperature

what is the relationship between phenotype and genotype?

-genotype is what is in your genes -phenotype if the appearance

what are snps?

-single nucleotide polymorphism, single base pair on a strand of DNA -can cause a different protein to be produced -can cause diseases

how can restriction enzymes and electrophoresis be used to identify snps and determine an individuals genotype?

-a restriction enzyme would cut the DNA in a specific place -the cut will change the size of the band during electrophoresis -can determine the genotype based on the amount of bands in the gel

medical interventions and lifestyle modifications that can help a pregnant women have a healthy pregnancy?

amniocentesis, CVS, ultrasounds, prenatal vitamins, exercise, healthy diets, obstetricians, gynecologists, c-sections, ultrasounds

what can amniocentesis and chorionic villus sampling tell a couple about their developing fetus?

chromosomal abnormalities, neural tube defects, genetic diseases, paternity

both ____ and ___ play a role in the development of disease

environmental and genetic factors

genetic disorder is a disease caused by ____

abnormalities in an individuals genetic material

single gene disorder

-caused by changed or mutation that occur in the DNA sequence of one gene

a gene

-segment of dna, contains instructions for the production of a protein

diseases and disorders result when a gene ____

is mutated resulting in a protein product that can no longer carry out its normal job

what 3 ways can a single gene disorder be inherited

autosomal dominant, autosomal recessive, sex-linked

multifactorial disorder

caused by a combination of environmental factors and mutations in multiple genes

heart disease and breast cancer are a type of

multifactorial disorder

many chronic illnesses are

multifactorial disorders

humans have ___ chromosomes in their body cells

46, 44 autosomes, 2 sex chromosomes

chromosomal disorders

where there are missing or extra copies of genes, or breaks, deletions, or rejoining of chromosomes

mitochondria

organelles in cells that convert every and contain DNA

mitochondrial disorder

rare, caused by mutations in non chromosomal DNA part of the mitochondria

mitochondrial DNA is passed from ___ to _____

mother to child

examples of carrier tests

tay-sachs disease or sickle cell disease

fetal screening/prenatal diagnosis

allows parents to diagnose a genetic condition in their developing fetus

examples of fetal screening/prenatal diagnosis

amniocentesis, chorionic villi sampling, and ultrasound

Duchenne muscular dystrophy

sex-linked, x chromosome has mutation

cystic fibrosis

single gene disorder,recessive disease, build up of mucus in the lungs, carriers

Huntington's disease

single gene disorder

down syndrome

chromosomal disorder

leber hereditary optic neuropathy

mitochondrial disorder, only passed from mother to offspring

alzheimers

multifactorial

polycystic kidney disease

causes cysts in the kidneys, autosomal dominant, newborn screening

marinas disease

causes over production of protein so limbs grow very long, autosomal dominant, single gene mutation

Fill in the blank: A(n) _______________ is a trained professional who helps individuals and families understand genetic testing options and the implications of undergoing genetic testing.

genetic counselor

What are the 4 types of genetic disorders?

single-gene, multifactorial, mitochondrial, and chromosomal

Fill in the blank: A(n) ________________ disorder can be classified as autosomal dominant, autosomal recessive, or sex-linked.

single-gene

Fill in the blank: A(n) ________________ disorder is caused by a combination of multiple "bad" genes and the environment.

multifactorial

Fill in the blank: A(n) ________________ disorder is fairly rare and is caused by mutations in the DNA of mitochondria. This makes it difficult for the body to produce ATP.

mitochondrial

Fill in the blank: A(n) ________________ disorder involve inheriting either not enough chromosomes or extras.

chromosomal

What type of disorder is Duchenne Muscular Dystrophy (DMD)?

single-gene, X-linked recessive

What type of disorder is Cystic Fibrosis?

single-gene, autosomal recessive

What type of disorder is Huntington's Disease?

single-gene, autosomal dominant

What type of disorder is Down Syndrome?

chromosomal, trisomy 21

What type of disorder is Leber Hereditary Optic Neuropathy?

mitochondrial

What type of disorder is Marfan's Syndrome?

single-gene, autosomal dominant

What type of disorder is Leukemia?

single-gene, autosomal dominant

What type of disorder is Phenylketonuria (PKU)?

single-gene, autosomal recessive

What type of disorder is Fragile X Syndrome?

chromosomal

What type of disorder is Hemophilia?

single-gene, X-linked recessive

Fill in the blank: __________________ is a genetic disorder characterized by progressive muscle degeneration and weakness.

duchenne muscular dystrophy (DMD)

Fill in the blank: __________________ is a progressive, genetic disease that causes persistent lung infections due to mucus buildup and limits the ability to breathe overtime.

cystic fibrosis

Fill in the blank: __________________ is an inherited disease that causes progressive degeneration of nerve cells in the brain.

huntington's disease