Deafblind syndromes, diagnostic tools and treatment

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1 Deafblind syndromes, diagnostic tools and treatment Claes Möller Department of Audiology Örebro University Hospital

2 Confusion Why is my child deaf? Why is my child clumsy? Why has my child problems at night? Why don t I like gymnastics and sports? Why can t I have a drivers licence? Why can t I hear, I have good hearing? Why can t I go on working in the factory? What is Deafblindness?

3 Despair I went to the doctor and he told me that I would go deaf and blind. He does not know why, not when, but it might be in the near future. Then the doctor abruptly left the room. No, not my hearing, not my vision!!!! It is not fair! How could God do this to me? Why wasn t I told until I was grown up? Somebody help me!!!!

Then the doctor abruptly left the room. No, not my hearing, not my vision!

4 Causes of Deafness Where do I start? What is known in the literature? Childhood Adult Recessive 38% X Linked 2% Recessive 5% X Linked 2% Nongenetic 30% Nongenetic 25% Dominant 30% Dominant 10% Unknown 25% Unknown 33%

5 98% Schimpans

7 Why is it important to know the cause? To get a correct diagnose To learn from other experiences To determine the prognosis of the disorder Progression of hearing loss. Usefulness of aids and/or cochlear implants. Progression of vision loss. Other associated symptoms.-dysfunctions Correct rehabilitations Treatments are expected to be specific to the cause One can avoid or justify other expensive tests. Patients and family often want and need a reason for the problem.

hearing loss. Usefulness of aids and/or cochlear implants. Progression of vision loss. Other associated symptoms.

8 Syndromal hearing losses, some problems 50% of children with HL have additional problems 30% of all hearing losses are syndromal >400 different syndromes Many rare syndromes Many different organs Ear and Eye most common (>100) Often starts as non-syndromic HL Difficult to diagnose

different syndromes Many rare syndromes Many different organs Ear and

9 Congenital deafblindness extremely rare often multiple disabilities Sensory deprivation- mental retardation? Severe communication problems life-long communication training cochlear implants have somewhat changed the outcome

Severe communication problems life-long communication

10 Aquired deafblindness Often congenital hearing loss/ profound deafness progressive visual loss >75 different syndromes 80-90% genetic Usher syndrome 50-60%

11 How do we diagnose possible deafblindness? Pedigree Vision Audiology Dysmorphology Neurology Balance Radiology Kidney Heart Viral Infections Cognition Genetics

12 Why A Mouse? Similarity to humans Large numbers to study Common background genetic modifiers Fast, inexpensive, & efficient

13 Some syndromes with deafblindness Usher Alström Refsum Waardenburg Norrie Charge Mitochondrial

14 Usher Clinical Types Type 1: Profound hearing loss (deaf). Early onset RP. Balance problems. Type 2: Moderate to severe hearing loss (hard of hearing) RP evident in their teens No balance problems Type 3: Progressive hearing loss. Looks like type 2 as children. Looks like type 1 as older adults.

Type 2: Moderate to severe hearing loss (hard of hearing) RP evident in

15 Teenage

16 40 50 years

17 Around 50 years with cataract

18 How Frequent Is Usher Syndrome? New studies type I 10% of deaf children Some data indicate that Usher type II is almost two times as frequent as type I Geographical variations The overall frequency of Usher is guesstimated at >10 per 100, worldwide

Usher type II is almost two times as frequent as type I

19 Genetic diagnose of Usher 2011 Screening for Usher using DNA-chip Screening at a reasonable cost Confirmation at a genetic lab Diagnose rapidly and accurate Diagnose early in the development of retinal dystrophy Early diagnoses provides early habilitation and treatment

Diagnose rapidly and accurate Diagnose early in the development of

20 Genetic subtype Locus Gene Protein USH 1B 11q13.5 MYO7A myosin VIIA USH 1C 11p15 USH 1C harmonin USH 1D 10q21-22 CDH23 cadherin USH 1E 21q21 USH 1F 10q21-22 PCDH15 protocadherin 15 USH 2A 1q32-42 USH 2A usherin USH 2B 3p23-24 USH 2C 5q14.3-q21 g-protein USH 3 3q21-q25 USH3 clarin

CDH23 cadherin USH 1E 21q21 USH 1F 10q21-22 PCDH15 protocadherin 15

23 Here are the genes for Usher syndrom Frolenkov et al.

25 CI and Usher Lif long commitment Rapid technical advances Early implantation in type I and III Different implants for different HL Short implants in type III Electro-acoustic hearing in type III

26 CI and Usher type 1 Most people with USH I will have CI 10% of all deaf children USH 1( Iowa, Sweden) Most USH1 undetected at time of implantation Habilitation not like non-syndromal deafness Second language sign language later tactile? Results if early implantation excellent Bilateral implantation Some persons USH 1 implanted at y Sound recognition

27 If I go blind and if CI don t work?

28 Can Usher syndrom be treated? Safety and geographic orientation Life style changes Smoking cessation Sunglasses Diet Vitamin supplementation and antioxidants Prosthetics Cochlear Implants Retinal Implants CNTF and other growth factors Aminoglycoside look alikes. Stem Cell Therapy Gene therapy

29 Prevention may be as simple as wearing sunglasses Animal studies suggest that light (uv and blue) accelerates the loss of rods and is especially damaging to Usher retinas Unproven in humans Depending upon the frequencies, filtering glasses may be appropriate even indoors.

30 Does vitamin supplementation slow the progression of RP? Harvard medical school. First study reported Vitamin A slowed the progression of RP. Later study showed a greater effect when in combination with diet (fish important). BUT, it remains controversial. +

31 Genterapi DNA för Protein X Protein X bildat från den infekterade cellen Virusvektor med genen för Protein X Cellkärna Målcell

32 CHARGE Coloboma Heart Atresia of the choanes Retardation Genital Ear abnormalities

33 Overview of features occurring in CHARGE syndrome (frequencies are shown in table 2). Bergman J E H et al. J Med Genet 2011;48: by BMJ Publishing Group Ltd

34 Coloboma

35 Clinical criteria for CHARGE Blake * (1998) Major criteria Minor criteria Inclusion rule 1. Coloboma, microphthalmia 2. Choanal atresia or stenosis 3. Characteristic external ear anomaly, middle/inner ear malformations, mixed deafness 4. Cranial nerve dysfunction 1. Cardiovascular malformations 2. Tracheooesophageal defects 3. Genital hypoplasia or delayed pubertal development 4. Cleft lip and/or palate 5. Developmental delay 6. Growth retardation Typical CHARGE: 4 major or 3 major + 3 minor 7. Characteristic face

36 Genetic diagnosis Mutation in CHD7 gene Usually spontanous mutations Autosomal dominant Relative risk for new siblings ca 2 %

37 Feature CHD7 mut.(n=280) Ext ear anomaly 97% 96% Cranial nerve dysf. 99% 86% Semicircular canal abn 94% 100% coloboma 81% 77% Choanal atresia 55% 61% Cleft lip/palate 48% 18% Feeding difficulties 82% 85% Facial palsy 66% 36% Inability to smell (anosmia) 80% CHARGE før CHD7-gen (n=124) Genital hypoplasia 81% 36% Zentner GE et al. Molecular and phenotypic aspects of CHD7 mutation in CHARGE syndrome. Am J Med Genet 2010; 152A:

38 Alström syndrome Hearing Infections Kidneys Skin Vision Heart Liver Metabolism -diabetes -obesity -cholesterol -etc.

39 Alström syndrome Symtom Ögon Öron Balans Hjärta Blodfetter Diabetes Njurar Lever Tänder Övervikt Bukspottkörtel 0 år 10 år 20 år 30 år 40 år

40 Anna 12 years Anna 21years

41 Genetics ALMS1 gene 2p13 Large gene 4 frameshift and 2 nonsense mutations Encodes an unknown protein Two mouse models, original, fat aussie

42 En normal mus

43 Alström mouse Alström Syndrome mouse

44 OPA1 a new deafblind syndrome Mutation affects mitochondria Optic atrophy Vision loss can be either optic atrophy or RP!! Progressive hearing loss, auditory neuropathy Deafness Neurological disorders, ataxia, neuropathy, tremor

45 PHARC en ny sykdom med ny sykdomsmekanisme Laurence Bindoff Eikholt Fagkonferanse August 2011

46 PHARC - acronym Peripheral neuropathy Hearing loss Ataxia & pyramidal tract (not all) Retinal pigmentation Cataract

47 Summary PHARC A clinically distinct syndrome Caused by mutations in ABHD12 World-wide distribution First neurodegenerative disorder linked to endocannabinoid metabolism

48 Multidisciplinarity in hereditary hearing impairment-examining the patient Genetic counselling GJB2 and other genes Family history Clinical photos Hearing impairment Bioinformatics CT scan, Eye exam, Renal US Array CGH Audiological profile Geography and ethnicity

49 Thank you!!!

Jennifer A. Defant, M.S., C.G.C. Certified Genetic Counselor Division of Genetics and Metabolism University of Florida

Jennifer A. Defant, M.S., C.G.C. Certified Genetic Counselor Division of Genetics and Metabolism University of Florida 60% of childhood hearing loss is genetic Syndromic Nonsyndromic 40% of childhood hearing