genetic counselling & genetic testing

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Genetic Counselling & Genetic Testing. What is Genetic Counselling?. Education and guidance offered by professional advisors in order to help people make informed decisions based on genetic knowledge. - PowerPoint PPT Presentation

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Page 1: Genetic Counselling  &  Genetic Testing
Page 2: Genetic Counselling  &  Genetic Testing

What is Genetic Counselling?

• Education and guidance offered by professional advisors in order to help people make informed decisions based on genetic knowledge.

• Combines providing information about genetic conditions with counselling support so that individuals can make personal decisions about the management of their health, their children’s health, or their pregnancies.

Page 3: Genetic Counselling  &  Genetic Testing

What is Genetic Counselling? Cont.

• Advisors help the person understand the meaning of specific information in their genes.

• Once the test results are looked over, the advisor helps the person decide whether to have a genetic test performed or what to do with the information provided by the test.

Page 4: Genetic Counselling  &  Genetic Testing

What is Genetic Counselling? Cont.

• Genetic Counselling may be helpful to people interested in knowing more about:

– The chances of having or developing an inherited condition

– A family history of cancer– A family history of a condition that might be inherited– The chances of having a child with an inherited

condition– Prenatal testing for high risk pregnancies

Page 5: Genetic Counselling  &  Genetic Testing

What is a Genetic Counsellor?

• Health care professionals with specialized training & experience in the areas of medical genetics and counselling.

• Provide individuals/families with information on the nature, inheritance, and implications of genetic disorders to help them make informed medical and personal decisions.

Page 6: Genetic Counselling  &  Genetic Testing

What do Genetic Counsellors do?

• Identify individuals and/or families who may have, or be at risk for, a genetic condition

• Investigate the problem present in the family• Interpret information about the disorder• Analyze inheritance patterns and risks of

occurrence and recurrence• Review available options with the

individual/family in a manner that promotes informed choice

Page 7: Genetic Counselling  &  Genetic Testing

What do Genetic Counsellors do? Cont.

• Help people understand & adapt to the medical, psychological, and familial implications of how genetics contributes to disease

• Guide individuals/families in discussions about test result interpretations, prevention, medical management, and options for prenatal diagnosis

• Provide supportive counselling to individuals/families with sensitivity to ethnic & cultural diversity and address potential ethical issues

Page 8: Genetic Counselling  &  Genetic Testing

What do Genetic Counsellors do? Cont.

• Serve as patient advocates & refer individuals/families to available support services

• Serve as educators/resources to other healthcare professionals & the general public

• Combine aspects of social worker/counsellor & medical professional

Page 9: Genetic Counselling  &  Genetic Testing

Types of Genetic Tests

• Tests based on DNA, RNA, chromosomes, protein• Testing parents for carrier status• Prenatal testing• Neonatal testing• Testing in children• Presymptomatic screening for late-onset disease• Presymptomatic screening for complex disease

susceptibility

Page 10: Genetic Counselling  &  Genetic Testing

Testing Parents for Carrier Status

• Carrier testing is used to identify people who carry one copy of a gene mutation that, when present in two copies, causes a genetic disorder.

• Offered to individuals who have a family history of a genetic disorder & to people in ethnic groups with an increased risk of specific genetic conditions.

• If both parents are tested, the test can provide information about a couple's risk of having a child with a genetic condition.

Page 11: Genetic Counselling  &  Genetic Testing

Testing Parents for Carrier Status

• Tests on parents can be performed on a sample of blood, hair, skin, amniotic fluid or other tissue. Sample is analyzed for abnormalities in chromosomes, DNA, or proteins

• Family trees (pedigree) often composed to trace the spread and hereditability of gene/disease

Page 12: Genetic Counselling  &  Genetic Testing

Testing Parents for Carrier Status

• Pedigree Analysis:– Pedigree diagram is used to

represent/map out genetic relationships– Used to determine the mode of

inheritance (autosomal dominant, autosomal recessive, X-linked recessive) of genetic disorders

Page 13: Genetic Counselling  &  Genetic Testing

Prenatal Screening

• Prenatal screening tests are used to check the health of a developing baby.

• Tests usually done early in pregnancy (<20 wk) • A screening test does not tell for sure that the

developing baby has a certain problem, but it does tell if it is more likely and if further testing is necessary.

• Most common prenatal tests check for a higher chance of chromosome problems like Down Syndrome, spina bifida...

• Examples of prenatal screening:– Maternal Serum Screen (MSS)– Ultrasound

Page 14: Genetic Counselling  &  Genetic Testing

Most Common Types of Prenatal Genetic Tests

• Amniocentesis– The most common prenatal test performed today

(Morris, 1993)– Estimated fetal loss - 0.5% (O’Connor, 1989)– Diagnostic test that involves examining cells shed

naturally from the fetus into the amniotic fluid– Can indicate chromosomal disorders like Down

syndrome, genetic disorders like Cystic fibrosis, and neural tube defects like spina bifida

– Usually for women 35+ or if questionable results from ultrasound

Page 15: Genetic Counselling  &  Genetic Testing

Most Common Types of Prenatal Genetic Tests

• Chorionic Villi Sampling– Can be performed at a much earlier age of the fetus

development compared to an amniocentesis test (as early as 8 weeks)

– Fetus is located through ultrasound; needle passed through the abdomen and fragment of chorionic villi (finger-like projections from the placenta) are extracted which carry identical genetic information

– Risk of having a miscarriage is slightly higher than amnio. (approx. 0.5-1%)

Page 16: Genetic Counselling  &  Genetic Testing

Most Common Types of Prenatal Genetic Tests

• Alpha-fetal protein Sampling (AFP)– A blood test from the mother that determines the variation

of high and low concentrations of alpha-fetoprotein in the mother’s blood that can indicate a risk of fetal genetic abnormalities

– Measured middle of the second trimester (14-16 weeks)– Elevated levels may be caused by neural tube defects

including spina bifida, anencephaly, and abdominal wall defects

– Abnormally low levels in Down syndrome and trisomy 18– High false positive rate– Tumour marker

Page 17: Genetic Counselling  &  Genetic Testing

Other types of Prenatal Screening

• Maternal Serum Screen (MSS)– Uses a blood sample from the mother’s arm to

measure the amounts of special substances found in every pregnant woman’s blood

– MSS provides helpful information that will allow one to determine the risk of having a baby with Down syndrome or spina bifida

– If the developing baby has Down syndrome or spina bifida, then the amounts of these substances may be slightly different than we usually expect.

Page 18: Genetic Counselling  &  Genetic Testing

Neonatal Testing• Newborn screening – process of testing newborn

babies for treatable genetic, endocrinologic, metabolic, and hematologic diseases.

• Ex. Phenylketonuria (PKU) screen– Obtaining blood sample from newborn baby’s heel to screen

for PKU – Autosomal recessive disorder characterized by deficiency in

hepatic phenylalanine hydroxylase necessary to metabolize phenylalanine (Phe) and tyrosine (Tyr)

– PAH deficiency causes accumulation of Phe which can be detected in urine

– Left untreated, condition can cause problems with brain development, leading to mental retardation, brain damage and seizures

– Easily controlled by low Phe diet; Damage is irreversible, hence early detection is crucial

Page 19: Genetic Counselling  &  Genetic Testing

Testing in Children

• If a child does not reach specific milestones (ex. Sit independently by 4-7 months, reach and grasp objects by 3 months, double birth weight by 4 months...) there may be cause for concern and health care professional may direct family to specialist/genetic counsellor

Page 20: Genetic Counselling  &  Genetic Testing

http://www.signaturegenomics.com/prenatal_microarray_services.html

http://thoroughgen.com/about-us.html

https://www.23andme.com/

http://www.illumina.com/products/human_omni_express_beadchip_kits.ilmn

https://www.youtube.com/watch?v=lVG04dAAyvY

Page 21: Genetic Counselling  &  Genetic Testing

What is the Value of Genetic Testing?

• When necessary, geneticists can test for some genetically determined conditions so couples considering having a child will know what the odds are of having a child with a particular disorder

• Testing is only done if a couple is at increased risk of having a child with a certain condition; based on their ethnicity, family trees, or medical history

• Testing can be done prior to conception or during pregnancy

• Testing is valuable since having a diagnosis provides basis for how a disorder should be managed

Page 22: Genetic Counselling  &  Genetic Testing

Who Seeks Genetic Counselling?

• Genetic counselling is appropriate for people who are concerned about:– A child with a genetically determined

condition and/or birth defect– Their own risks of having a genetically

determined disorder, or of having a child with a problem due to medical family history or ethnic background

– Pregnancy at 35 years or older– Exposure to potentially harmful

substances during pregnancy

Page 23: Genetic Counselling  &  Genetic Testing

Genetic Counselling as a Career• Genetic counsellors complete a Master of

Science degree in genetic counselling from a recognized university program.

• Typical educational backgrounds include: biology, nursing, social work, psychology...

• Training consists of course work in genetics & counselling theory, as well as clinical rotations within genetics departments.

• In Canada, most genetic counsellors are certified by the Canadian Association of Genetic Counsellors.

Page 24: Genetic Counselling  &  Genetic Testing

Schools/Programs in Canada• UBC, U of T, McGill

– Genetic Counselling (M.Sc.)

– LENGTH OF PROGRAM• 2 years

– NUMBER OF STUDENTS ACCEPTED EACH YEAR• Approx. 6-10

– TUITION• Approx. $30, 000

– INCOME• $45, 000 - $50, 000 depending on location

Page 25: Genetic Counselling  &  Genetic Testing

Schools/Programs in Canada

• The Michener Institute (Toronto)– Genetics Technologist (Diploma)– Processing specimens for genetic analysis – Analyze chromosomes, DNA and RNA for genetic abnormalities and help diagnose,

treat and monitor disease.

– REQUIREMENTS:• Bachelor of Science degree with two or more university-level genetics courses

(either in Human Genetics or Molecular Genetics).

– NUMBER OF STUDENTS ACCEPTED / APPLYING EACH YEAR:• 16 out of 50 interviews

– LENGTH OF PROGRAM:• 16 months

– TUITION:• $4, 500

– INCOME:• $45,000 - $60,000 per year, depending on location.

Page 26: Genetic Counselling  &  Genetic Testing

Schools/Programs in Canada• BCIT (Vancouver)

• British Columbia Institute of Technology

– Genetics Technologist (Diploma) Genetics Technologist (Diploma)– Processing specimens for genetic analysis – Analyze chromosomes, DNA and RNA for genetic abnormalities and help diagnose, treat

and monitor disease.

– REQUIREMENTS:• Bachelor of Science degree with two or more university-level genetics courses (either

in Human Genetics or Molecular Genetics) with a minimum grade of 60%.

– LENGTH OF PROGRAM:• 16 months

– TUITION:• $7, 500

– INCOME:• $45,000 - $60,000 per year, depending on location.

Page 27: Genetic Counselling  &  Genetic Testing

Other Career Options

• Medical Geneticist (MD)– Clinical/academic geneticist. Oversees patient

diagnosis, treatment & referral. Often leads a multidisciplinary team. An experienced MD with specialization in clinical genetics.

– LENGTH OF PRORGRAM• 4 year MD + 6-9 years specialty & subspecialty

Page 28: Genetic Counselling  &  Genetic Testing

Other Career Options

• Graduate School (PhD)– Geneticist/molecular biologist.– Wide field of study, from basic cellular and molecular

biology, to searching for diseased genes, to tracking spread of disease.

– LENGTH OF PROGRAM• 4-6 years

– INCOME• Pharma. Industry: $100, 000+• Academia: ???

Page 29: Genetic Counselling  &  Genetic Testing

Other Career Options

• Intellectual Property Law– MSc/LLB/LLM/Patent Agent– Scientific background (BSc/MSc) with a law

degree and specialization

– LENGTH OF PROGRAM• 3 Years (Law School)

– INCOME• Pharma. Industry: $100, 000+• Private firm: $80, 000 - $500,000+

Page 30: Genetic Counselling  &  Genetic Testing

23 and the RCMP

• http://www.rcmp-grc.gc.ca/nddb-bndg/index-accueil-eng.htm