1 of 46

BUILDING A BETTER PARTNERSHIP: WHAT GENETICS CAN DO FOR YOU

Tahnee N. Causey, MS, CGC

Lead Genetic Counselor, VCU Health, Richmond, VA

Director, MS in Genetic Counseling Program

2 of 46

DISCLOSURES

I am a dual employee of the Commonwealth of Virginia and VCU Health in Richmond, VA
Sadly, no financial disclosures.

3 of 46

WHY GIVE THIS TALK?

We share common goals

People first, always
Collaboration
Support

This Photo by Unknown Author is licensed under CC BY-SA

4 of 46

WHY GIVE THIS TALK?

We have a reciprocal relationship

Many individuals with intellectual or developmental disabilities have an underlying genetic diagnosis
Many of your families may be referred to genetics for evaluation at some point in their journey
Many of the families we work with are referred for early intervention or support services after being seen by Genetics

5 of 46

WHY GIVE THIS TALK?

Demystifying a genetics referral and evaluation can help families and providers alike
Information is power=knowing what genetics can do helps families and helps providers help families

6 of 46

GOALS FOR TODAY

Who is involved in a genetics visit? What happens during this visit?

Common reasons for referral for genetics

Genetics 101

Genetic testing

Ways to access genetics providers

7 of 46

FUN FACTS ABOUT GENETICS

Unless you are an identical twin, your combination of genes is unique.

People have 20,000 genes.

Goldfish have more genes than humans do

8 of 46

WHO, WHEN, WHY, AND HOW?

9 of 46

WHO IS INVOLVED IN A GENETICS VISIT?

For most pediatric genetics visits, you’ll meet with two primary individuals:

Medical Geneticist

Physician who has completed residency (usually in Pediatrics) and then completed an additional two year fellowship in Medical Genetics
Completes a physical exam, provides diagnosis, orders testing, like other physicians

Genetic Counselor

Not a physician-holds a master’s degree in genetic counseling
Works closely with physician by gathering medical and family history, facilitating genetic testing and relaying results and arranging follow-up

10 of 46

GENETIC COUNSELORS

Often the family’s main point of contact before and after a visit, sometimes for months after a visit
Interpret family and medical history to assess risk of occurrence/recurrence
Help family understand/adapt to medical, psychological, and familial implications of diagnosis (or lack of diagnosis)
Educate about inheritance, testing, management, prevention, resources, and research
Promote autonomous, informed choices!

This Photo by Unknown Author is licensed under CC BY

11 of 46

GENETIC COUNSELORS TAKE A DETAILED FAMILY HISTORY

12 of 46

HOW? ANATOMY OF A GENETICS VISIT

Medical history-what features have led the family to this appointment?

Family history-are there family members with similar or overlapping features?

Physical exam

Discussion of possible diagnoses and available testing

Plan for follow-up, including referrals, testing, return visits

Plan for 60-90 minutes

13 of 46

WHEN SHOULD A FAMILY BE REFERRED TO PEDIATRIC GENETICS?

Developmental delay/intellectual disability

Abnormal newborn screening results/blood tests

Muscle tone differences

Developmental plateau or regression

Unusual skin findings or markings

14 of 46

WHEN SHOULD A CHILD BE REFERRED TO GENETICS?

Multiple affected family members

Multiple birth defects—either major or minor

Short/tall stature

Hand/foot/limb differences

Microcephaly/macrocephaly

Hemihypertrophy/atrophy

Child looks significantly different than other family members

15 of 46

OTHER REASONS TO REFER TO GENETIC COUNSELING OUTSIDE OF PEDIATRICS

Maternal age >35

Recurrent pregnancy loss

Family history of cancer

Early ages of onset
Multiple relatives with the same or related cancers
Multiple cancers in one individual

16 of 46

WHY? WHAT BENEFITS CAN FAMILY RECEIVE FROM GENETICS EVALUATION?

Explanation of cause, recurrence risks

More accurate information on short, long term prognosis

Appropriate referrals, intervention, medical management

Treatment options, e.g. clinical trials, research, etc.

Support resources specific to condition

17 of 46

GENETICS 101

20 of 46

GENETIC TESTING MAY START WITH BASIC CHROMOSOME ANALYSIS

21 of 46

HOW IS CHROMOSOME ANALYSIS COMPLETED?

Blood is most common specimen
Buccal (cheek) swab

24 of 46

MOST COMMON BASELINE TEST: CHROMOSOMAL MICROARRAY

Chromosomal microarray is a comprehensive test looking at all chromosomal information simultaneously and can identify:

Whole extra or missing chromosomes
Small or large missing portions of chromosomes (deletion)
Small or large extra portions of chromosomes (duplication)

25 of 46

DELETIONS/DUPLICATIONS

May be well known conditions
May be rare but clearly causative of problems because of size of DNA involved
Significance may also be unknown

26 of 46

MICROARRAY TELLS US OVERALL WHAT GENES ARE INVOLVED

27 of 46

WHAT HAPPENS IF MICROARRAY IS NORMAL?

The medical geneticist might recommend specific testing for one or more genes based upon a suspected diagnosis
Gene testing is more specific and detailed than microarray
If a genetic condition is due to just one gene, then testing is straightforward and targets the one gene
If a genetic condition is due to a number of genes, then the genetics team must select the panel of genes that is the best fit for patient & most cost effective

30 of 46

WHAT HAPPENS IF TESTING IS POSITIVE?

A diagnosis is established

The exact genetic cause is identified
Family can receive information about common features, inheritance, and (general) information about prognosis
Appropriate referrals can be facilitated

31 of 46

GENETIC CONDITIONS MAY HAVE IMPLICATIONS FOR OTHER RELATIVES

Genetic changes may be de novo or brand new to the individual
Some changes are recessively inherited, meaning one non-working gene is inherited from each parent, so child has no working copies of that gene
Some changes are dominantly inherited, meaning one parent has the same condition and passed the non-working gene to the child
Some changes are located on the X chromosome and therefore chromosomal gender influences expression

35 of 46

WHAT IF GENETIC TESTING IS NEGATIVE?

More comprehensive testing is available-whole exome or whole genome sequencing

Expensive ($7000 and up) and not all insurance companies will cover this testing

There’s a lot we don’t know!

Trio testing is most informative

36 of 46

EXOME VS GENOME

The exome is the portion of the genome that makes proteins

85% of human genetic conditions occur due to changes in the exome

We don’t have a good understanding of what non-protein coding DNA does!

39 of 46

WES VS WGS

With parents and child, WES provides a definitive diagnosis in ~30% of tests

WGS may provide a definitive diagnosis in another 7%, so ~37% detection

A negative WES/WGS doesn’t mean there is no genetic cause-we just don’t know what that genetic change is yet

40 of 46