Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
41 Cards in this Set
- Front
- Back
|
Genetic counselor |
Healthprofessional trained in genetics and counseling Foundin:Prenatal,Pediatric, Cancer, Adult, Sub-specialty clinics, Industry, Laboratories Educatepatients and families about:Genetics,genetic testing, test results, prognosis, community/national resources Facilitatedecision making Aidin adjustment |
|
|
Nursing and genetics practice |
Patientmanagement role Healtheducation role Psychosocialsupport role Patientadvocacy role Familiarity with sensitivity &specificity of routine genetic testing/screening to ensure our patient’sautonomy “Informed consent”—about genetictesting/screening/treatment/intervention |
|
|
Chromosomes |
Like beads on a string all different sizes and shapes - which is why you can tell which one is which |
|
|
Karyotype |
Separatingthem out is done by visual inspection |
|
|
Chromosome abnormatlities |
Toomany – down syndrome Toofew – turner syndrome Extrapieces (duplications) Missingpieces (deletions)Piecesthat switch places (translocations) Balanced - usually completely healthy because theyhave all their genetic info Unbalanced-can lead to health issues Balanced person is at risk to have a babywith unbalanced chromosomes |
|
|
Trisomy vs triploidy |
Trisomy- 3rd of only one of the genes Triploidy- 3rd copy of all the chromosomes --> would result in a 1st trimester miscarriage |
|
|
Too few chromosomes |
Turner syndrome- Girl with only one sex chromosome short, some differences with heart and kidneys, some learningdifficulties. Infertile. They will not go through puberty. Overall girls withturner syndrome do quite well. Sometimes they take oral hormones but thisdoesn’t make them normal |
|
|
Screening related to genetics |
Carrier screening- youdo not have any outward features of the disease which is why it’s important toget tested. We are thought to be carriers for 10-12 recessive diseases Aneuploidy- wrong number of chromosomes, too many or too few Universal Carrier Screening- Screenfor 100+ conditions regardless ofethnicity Futureof carrier screening |
|
|
Ethnicity based carrier screens |
Hemoglobin electrophoresis- done on everyone Hemoglobinopathies (African/African-American/Asian/Mediterranean)1/12African Americans (Hb AS) 1/30(HbAC) Thalassemias 1/30Asian (alpha-thal) 1/7-1/100(Beta-thal) |
|
|
Cystic fibrosis |
caucasian- 1/25 carrier frequency trouble with their lungs- wear percussion vestsin the morning to make it easier to breathe more susceptibleto sticky secretions and bacterial infections Usually will need lungtransplant or will die pancreas doesn’t secrete digestiveenzymes-might not absorb nutrients correctly |
|
|
Tay-sachs |
AshkenaziJewish 9Conditions we should def test for 1/30-1/100carrier frequency French Canadian |
|
|
Aneuploidy- done for all pregnant women via blood test |
Abnormalnumber of (entire) chromosomes Historicallybased on maternal age Basedon frequency of live births Downsyndrome (trisomy 21) (1/800) Trisomy18 (1/3-5000) Trisomy13 (1/8000) |
|
|
Proportion of chromosome abnormalitiesand maternal age |
Most babies w/ chromabs born to couples under age 35 b/c they have more children compared to oldercouplesAnd chrom abnormalities are such an integralpart of nature |
|
|
Down syndrome (trisomy 21) |
Most common chromosome abnormality most have heart defects, many genetic defects, often hydrocephalusat birth, developmental delay and mental retardation. They hit developmentalmilestones later. They now live well into their 60s. Most common single cause of mentalretardationgenetic but not inherited 2/3 fetuses do not survive to term Noneed to test parents |
|
|
Trisomy 18 |
Birth defects head to tow Cleft lip andpalate Hands are always clenched during pregnancy. Also clubbed foot- Theseindicate how severely effected the brain is. The brain doesn’t tell the baby tomove hands or feet. They have GI issues and they are born small. Most miscarryor die shortly after birth- within 1 year |
|
|
Trisomy 13 |
Severecondition Typicallyconsidered lethal- die within 1st year Associatedwith a number of severe defects- Brainanomalies, Heartdefects , Midlinedefects, Limbanomalies, Lowmuscle tone Holoprose encephaly- brain does not divide into twospheres-- it’s one big lump The face also doesn’t have a midline proboscus- a primitive nose |
|
|
Screening vs. diagnostic testing |
Screening- provides a personalized risk assessmentEveryoneis offered screeningIdentifythose at high risk from the general population Diagnostic testing provides a yes or no answerTypicallyonly high-risk individuals have diagnostic testing |
|
|
1st trimester screening |
Targetedultrasound -Viablepregnancy, Nuchaltranslucency, Largestructural anatomy Biochemicalanalysis- Free-βHCG; PAPP-A, “Personalized”risks for Down syndrome, trisomy 18and trisomy 13>90%detection rate |
|
|
U/S 11 weeks - 13 weeks 6 days <3.0mm |
Nuchal translucency – this is the whitefluid behind the baby’s neck. extra fluid --> could indicate Down syndrome |
|
|
1st trimester diagnostic testing CVS- used for high risk, looks at chromosomes Biopsy of the placenta Mom gets lidocaine, feels a little crampy |
11-14weeks GA Chromosomes 1/200miscarriage riskMaternalcell contaminationMosaicism |
|
|
2nd trimester screening ideally done at 18-20 weeks GA |
Targetedultrasound- AnatomyDopplermeasurements Biochemicalanalysis- Maternalserum “quad” screen, Lessaccurate than first trimester, EXTREMELYdependent on gestational age AFP only (also called a quad screen).Offeredto every woman- Screensfor neural tube and ventral wall defects |
|
|
2nd trimester testing amniocentesis |
16+weeks GA Chromosomes,AFP/AChE, virals 1/400risk of miscarriage- lower risk than CVS Results take longer |
|
|
FISH Fluorescent in situ hybridization |
> 90 % accurate 2-4 day TAT |
|
|
Karyotype (world view) |
large structural rearrangements 1-2 week TAT |
|
|
Microarray (street view) |
1-3week TAT Microdeletionsand duplications Riskfor variants of uncertain significance Reportedin # of bases and location |
|
|
NIPT non-invasive prenatal testing |
Fetalcell-free DNA in mom’s circulation Quantificationof DNA (“counting” or SNP analysis) Asearly as 9 weeks GA Highestdetection rate available for Downsyndrome (>99%)trisomy18 (>98%)trisomy13 (79-99%) Canreport on gender Alsoscreens for sex chromosome aneuploidyXO,XXX, XYY, XXY |
|
|
After screening/diagnosis |
Additionalscreening as needed (cell-free fetal DNA?) Altermanagement as indicated by condition or patient desire Planfor delivery may be altered - being at a qualified hospital to handle high risk birth Anticipatoryguidance for families |
|
|
Other uses of genetics |
Managementof personal diagnoses Managementor testing based on family historyManagementbased on clinical ultrasound findings |
|
|
Other potential genetic associations |
Sonogramfindings: Cleftlip/palate Heartdefects Brainmalformations Limbanomalies GImalformations |
|
|
ZIKA |
Classof arbovirus (iewest nile, dengue, chikungunya) Arthropodborn (mosquitos) Firstidentified in Uganda Symptomsgenerally mild and nonspecific 1in 5 have symptoms Onsetwithin a few days to two weeks of infectionFever,rash, joint pain, conjunctivitisRarelycauses Guillain BarresyndromeInfectionin pregnancy has been associated with microcephaly |
|
|
ZIKA transmission |
Most moms don't have symptoms transmitted through blood Transmission- person infected, transmitted to baby or mosquito bites infected person, acquires ZIKA, and then bites and transmits to other people |
|
|
ZIKA infection in pregnancy |
Screenat every prenatal visit for symptoms Laboratoryscreening- rRT-PCR(serum and urine) within 2 weeks of exposure/symptomsPositive- recent zika virus infection IgM2-12 weeks after exposure/symptoms Ifpositive, plaque reduction neutralization test (PRNT) IfpositiveConsideramniocentesis Serialultrasounds throughout pregnancy |
|
|
ZIKA prevention/treatment |
Currentlyno treatment or vaccine available Traveladvisements for pregnant women and their partners Delaypregnancy for 8 weeks if zika exposure Delaypregnancy for 6 months if male infectedIfpregnant with travel to areas with endemic zika, condom use throughout pregnancy Mosquitorepellants (ie, DEET)Mosquitonets do not work – active during the day Protectiveclothing Vaccineprojected 2018 |
|
|
Newborn health |
Newborn ScreeningOfferedin all states 32+metabolic, endocrine, genetic conditions – these are diseases that requirestarting treatment immediately Carein the newborn period may be altered depending on results on this testing Feeding/fasting,additional testing Heal prick down at delivery- false positives and false negatives. |
|
|
Womens health |
Managementby personal diagnosis or family history : Heartdisease, Diabetes, Othermultifactorialconditions CancerriskDeterminedby:Lifestylefactors, Exposures, Familyhistory |
|
|
Cancer risk |
Inheritedcancer “syndromes” 5-10%of breast cancers 10-15%endometrial cancers 10-15%ovarian cancers Canincrease risk for other cancers Dependenton specific syndrome Mayalter screening modality |
|
|
Cancer risk |
Breast,ovarian, endometrial cancer Fullevaluation of family history for: Numberof affected relatives/degree of relationTypeof cancer Ageof onset Overallsize of family structure Evaluationof appropriate/available testing Determinationof management Personalizedscreening protocol |
|
|
Breast Cancer genes BRCA1/BRCA2 |
BRCA genes severely raise the risk ofbreast cancer If they had breast cancer, maybe smart toremove the ovaries Tumorsuppressor genes, Autosomal dominantLifetimebreast cancer risk: up to 87%Lifetimeovarian cancer risk: up to 44%Highercarrier frequency in Ashkenazi Jewish population |
|
|
Possible Results |
Positive Eachfirst degree relative (sibling, child) is at 50% risk Additionalscreening indicated Potentialsurgical recommendations Negative Interpretationdepends on personal and family history Donot test children (or sibs if patient is unaffected) Variantof Uncertain significance (VUS) Waitand see |
|
|
Other syndromes |
HNPCC/Lynchsyndrome-Increasedrisk for colon cancer, endometrial cancer, ovarian cancer, gastric cancer Hereditarydiffuse gastric cancer - Increasedrisk for lobular breast cancer |
|
|
Issues with genetic testing |
Cost Accessibility/availability Results- Positive,Negative, Variantof uncertain significance ELSI(ethical, legal, and social implications)Discrimination(?) -- GINA, Right-to-knowvs. right not-to-know, Policyand legislationReligious,ethical concerns in context of society |
