Presentation is loading. Please wait.

Presentation is loading. Please wait.

Hearing Loss & Genetics: Understanding the Basics Anna Frangulov, B.S. Research Coordinator Childrens Hospital Boston.

Similar presentations


Presentation on theme: "Hearing Loss & Genetics: Understanding the Basics Anna Frangulov, B.S. Research Coordinator Childrens Hospital Boston."— Presentation transcript:

1 Hearing Loss & Genetics: Understanding the Basics Anna Frangulov, B.S. Research Coordinator Childrens Hospital Boston

2 Why Hearing Loss is So Common?

3 Structure of the Ear

4 Sound wave Inside the Cochlea snail Hair Cells Nerve

5 Structure of the Ear Conductive HL Sensorineural HL

6 Genetic Infections Drug-Related Structural What Causes Hearing Loss? Unknown Traumas/ Exposures Non-Genetic

7 How Genetic HL occurs?

8 Chromosomes in Nucleus 23 Pairs of Chromosomes MOM DAD

9 One Chromosome Pair Genes instruction manual

10 Genes

11 Chromosome Pair Genes Mutation error

12 How Is Mutation Inherited? Dominant ~15% Dominant ~15% Recessive ~80% Recessive ~80% X-Linked ~2% X-Linked ~2% Mitochondrial >2% Mitochondrial >2%

13 Dominant Inheritance Mutation error"

14 Carrier Mutation error"

15 How a Recessive Mutation is Passed? Carrier –No Hearing Loss Affected Child Hearing Loss

16 Recessive Inheritance

17 If a parent has a dominant mutation, EACH of their children has a 50% chance of having hearing loss Dominant Inheritance Recessive Inheritance 90% of all children w/HL have normal hearing parents! Parent w/HL Parent w/o HL Child w/HL If two parents have a recessive mutation, EACH of their children has a 25% chance of having hearing loss

18 HOW? WHO? WHY?

19 HOW Do We Know If HL is Genetic?

20

21 WHO Should Have a Genetic Test? Case A: Syphilis Case A: Syphilis Case B: CMV Case B: CMV Case C: Prematurity Case C: Prematurity Case D: High bilirubin level Case D: High bilirubin level Everybody with Sensorineural HL Also 2 Mutations in Cx26!!

22 WHY Should We Have a Genetic Test?? Benefits for Genetic Testing a definite cause a definite cause family members realize that they are carriers & determine risk factors for future children family members realize that they are carriers & determine risk factors for future children helps to find appropriate treatment/ management helps to find appropriate treatment/ management

23 Limitations for Genetic Testing does not necessarily find the answer does not necessarily find the answer severity of HL may not be predicted severity of HL may not be predicted a person may have mutations, but not have HL a person may have mutations, but not have HL

24 Things to Consider Things to Consider 1. Talk to knowledgeable professional Primary Care/ Pediatrician ENT Audiologist Clinical Geneticist Genetic Counselor Genetic Counselor Clinical Molecular Geneticist Clinical Molecular Geneticist

25 Things to Consider 2. What tests are done? Cx26 Cx26 Cx30 Cx30 Mitochondrial Tests Mitochondrial Tests Pendred Pendred 3. Cost

26 UNDERSTANDING TEST RESULTS (example Cx26)

27 What Does the Result Mean? Two Mutations are Found Two Mutations are Found No Mutations are Found No Mutations are Found Mutations w/Unknown Significance Mutations w/Unknown Significance One Mutation is Found One Mutation is Found ?? ~10% ~70% ~18% ~1%

28 One Mutation Found Mutation unrelated to deafness Mutation unrelated to deafness Test did not find 2 nd mutation Test did not find 2 nd mutation Dominant mutation Dominant mutation There may be a mutation in another gene There may be a mutation in another gene

29 Future in Genetics and HL More Genetic Tests More Genetic Tests GeneChip Technology

30 Research Studies Connexin 26 Study- individuals with Cx26 mutations Connexin 26 Study- individuals with Cx26 mutations Genetic Testing and Counseling Study - If you or your child has had genetic testing for hearing loss and you are willing to fill out a questionnaire Genetic Testing and Counseling Study - If you or your child has had genetic testing for hearing loss and you are willing to fill out a questionnaire GeneChip Study - individuals with hearing loss who and parents with normal hearing GeneChip Study - individuals with hearing loss who and parents with normal hearing Novel Gene Discovery Study - five or more family members with hearing loss Novel Gene Discovery Study - five or more family members with hearing loss

31 Now also in Spanish! Educational Material

32 Helpful Information Genetic Counselor - Rebecca Madore call to set an appointment or Genetic Counselor - Rebecca Madore call to set an appointment or Department of Clinical Genetics – To make appointment with Clinical Geneticist call Department of Clinical Genetics – To make appointment with Clinical Geneticist call National Society of Genetic Counselors (NSGC) National Society of Genetic Counselors (NSGC) Research Study Participation & Booklets Orders: Research Study Participation & Booklets Orders: Anna Frangulov or or


Download ppt "Hearing Loss & Genetics: Understanding the Basics Anna Frangulov, B.S. Research Coordinator Childrens Hospital Boston."

Similar presentations


Ads by Google