1. Basics of Genetic Assessment and Counseling 1 Dr Mohamed Fakhry

2. What is Genetic Counseling? Communication process Medical education of affected individuals and the general public concerning inherited disorder. Address individual concerns relating to development / transmission of hereditary disorder Genetics counselors are health care professionals with specialized graduate degrees and experience in medical genetics and counseling. Consultant = individual who seeks genetic counseling 2 Dr Mohamed Fakhry

3. When to see a Genetics Counselor About 3% of babies are born with birth defects each year, according to the U.S. Centers for Disease Control and Prevention - and of the malformations that do occur, the most common are also among the most treatable. The best time to seek genetic counseling is before becoming pregnant, when a counselor can help assess your risk factors. But even after you become pregnant, a meeting with a genetic counselor can still be helpful.

4. What Information should be provided? Medical diagnosis and its effects in terms of prognosis and possible treatment Mode of inheritance of disorder and the risk of developing and/or transmitting it Choices or options available for dealing with the risks 4 Dr Mohamed Fakhry

5. Steps in Genetic Counseling Diagnosis : based on history, examination and investigations Risk assessment Communication Discussion of Options Long-term contact and support 5 Dr Mohamed Fakhry

6. Establishing the Diagnosis Most crucial step in any genetic counseling If incorrect - totally misleading information could be given with tragic consequences Reaching diagnosis involves three fundamental steps Taking a history Examination Undertaking appropriate investigations 6 Dr Mohamed Fakhry

7. Information about consultand’s family is obtained by skilled genetics nurse or counselor Pre-clinic telephone or home visit is helpful Clinic visit - full examination Appropriate tests - chromosomes, molecular studies, referral to specialists (neurology, ophthalmology) Problems: Genetic heterogeneity, and Etiologic heterogeneity 7 Dr Mohamed Fakhry ⇝ Establishing the Diagnosis

8. Techniques Karyotype Aminocentesis Tests for abnormalities of chromosomes 1

9. Techniques This is a common test used to determine the risk of a child having a genetics disorder that his ancestors were carriers for Pedigree Analysis 2

10. Genetic Heterogeneity def - disorder that can be caused by more than one genetic mechanism Charcot-Marie-Tooth AD, AR, XR Retinitis Pigmentosa AD, AR, XR 10 Dr Mohamed Fakhry

11. Charcot-Marie-Tooth - also known as hereditary motor and sensory neuropathy type I (HMSN I) has been shown to result from a small duplication on short arm of chromosome 17 If found - this would aid in counseling 11 Dr Mohamed Fakhry ⇝ Genetic Heterogeneity

12. Etiologic heterogeneity Even though firm diagnosis - several causes may be possible eg. Deafness and non-specific mental retardation  Environmental or genetic factors 12 Dr Mohamed Fakhry

13. Calculating and Presenting the Risk Straightforward counseling situations - little more than knowledge about Mendelian inheritance is needed Problems: Delayed age of onset Reduced penetrance Use of linked markers can make calculations more complex 13 Dr Mohamed Fakhry

14. Presenting the Risk Presenting the Risk Parents must be given as much background as possible Recurrence risks should be quantified, qualified and placed in context 14 Dr Mohamed Fakhry

15. Quantification Most prospective= future parents will have some concept of risks Experience demonstrates that some common misinterpretations occur  a risk of 1 in 4 may be remembered as 4 to 1, 1 in 40, or even 14% !!!  The risk only applies to every fourth child !! It is ital to emphasize that the risk applies to each child, and that chance does not have a memory 15 Dr Mohamed Fakhry

16. Discussing the Options Provide consultants with all information needed to arrive at their own informed decision Details of all the choices open to them - include a complete discussion of reproductive options Alternative approaches to conception - AID, donor ova Review of techniques, limitations and risks associated with methods available for prenatal diagnosis 16 Dr Mohamed Fakhry

17. Communication and Support Communication - two way process Counselor provides information Receptive to fears and aspirations (hopes): expressed or unexpressed by consultant Information - present in clear, sympathetic and appropriate manner 17 Dr Mohamed Fakhry

18. Communication and Support Individual or couple will be extremely upset (worried) when first aware of a genetic disorder Complex psychological and emotional factors can influence counseling dialogue Setting - agreeable, private and quiet, with more than enough time for discussion and questions 18 Dr Mohamed Fakhry

19. Counseling Session can be so intense and insure that the amount and accuracy of information retained is not disappointing Letter summarizing the topics discussed at counseling session is often sent to family Follow-up home visit or clinic appointment to clarify any confusing issues 19 Dr Mohamed Fakhry

20. Special Problems in Genetic Counseling Consanguinity Adoption= التبني and genetic disorders Disputed Paternity 20 Dr Mohamed Fakhry

21. Paternity Testing Genetic fingerprinting using minisatellite repeat sequence probes Pattern of DNA fragments generated by those probes is so highly polymorphic that the restriction map is unique to each individual Specific as fingerprints 21 Dr Mohamed Fakhry