Understanding Genetic Syndromes Impacting Hearing Loss

1. Genetic Syndromes Carol Rousseau, M.A., CCC-A Rochester Hearing and Speech Center Rochester, New York 15 October 2004

2. Genetic Syndromes • Syndrome is a pattern of abnormalities and/or symptoms that result from the same cause. • More than 400 hereditary syndromes that involve hearing loss have been identified. • Different syndromes are associated with various types and degrees of hearing loss.

3. Genetic Syndromes (Cont) • Congenital vs. delayed onset and/or progressive. • Other physical and/or cognitive abnormalities. • Genetic locations.

4. Genetic Syndromes • Four Categories of Inheritance: • Autosomal Dominant • Autosomal Recessive • X-linked • Chromosome Abnormality

5. Autosomal Dominant • Waardenburg’s Syndrome • Treacher-Collins Syndrome • Alpert Syndrome • Alport Syndrome (types I,V,VI) • Crouzon Syndrome • Osteogenesis Imperfecta • Stickler Syndrome

6. Autosomal Dominant (cont) • Brancbio-Oto-Renal Syndrome (BOR) • CHARGE • Clefting Syndrome • Klippel-Feil Syndrome • Marfan’s Syndrome • Alport’s Syndrome

7. Waardenburg’s Syndrome • 2-5% of individuals with congenital hearing loss have this syndrome • Two types have been defined • Congenital • Sensorineural, however hearing ranges from normal to profound unitlateral or bilateral

8. Waardenburg’s Syndrome (Cont) • Other characteristics: • White forelock in hair or premature greying • Prominent root of nose • Different colored eyes • Inner ear dysplasia • Usually normal intelligence

9. Waardenburg’s Syndrome -- Type I • Almost total deafness with some residual hearing in the low frequencies • Always includes lateral displacement of the inner corner of the eye • 2q

10. Waardenburg’s Syndrome -- Type II • Moderate deafness with uniform hearing loss in the lower and middle frequencies but with improvement in the higher tones • Progressive hearing loss • 3q

11. Waardenburg’s Syndrome -- Type III • A severe form, also called Klein-Waardenburg • Partial albinism

12. Waardenburg’s Syndrome

13. Treacher Collins Syndrome • Congenital • Bilateral Conductive or mixed

14. Treacher Collins Syndrome (Cont) • Other characteristics: • Facial anomalies (depressed zygomatics, eyes slant downward laterally, receding mandible, mouth large and fish-like, dental anomalies, cleft palate). • Outer and middle ear deformities. • Typically normal intelligence, though mild mental retardation has been reported. • 5q

15. Treacher Collins Syndrome

16. Alpert Syndrome • Congenital • Mild to moderate Conductive Hearing Loss • Other characteristics: • Craniofacial anomalies affecting the ears (low-set) • Stapes fixations • Fused fingers & toes • Spina bifida • Most have some degree of mental retardation

17. Alport Syndrome (Types I, V, VI) • Delayed onset; progressive • Sensorineural hearing loss • Other characteristics (varies by type): • Renal disease • Ocular disorders • Blood platelet defect • 2q

18. Stickler Syndrome • Congenital or progressive • Conductive or Sensorineural • Other characteristics: • Cleft palate • Myopia • Renal detachment • Often associated with Pierre Robin Sequence (30% of infants with Pierre Robin have Stickler) • Normal intelligence • 12q or 6p

19. Bronchio-Oto-Renal Syndrome (BOR) • Congenital or delayed onset • Sensorineural, Conductive, or Mixed (depending on area affected) • Other characteristics: • Outer, middle, and/or inner ear deformities • Brancial fistulas/cysts • Renal disorders • Normal intelligence • 8q

20. CHARGE Association • Acronym for a group of anomalies that often appear together • 85% have some degree of hearing loss (conductive, sensorineural, or mixed • Stands for: • Coloboma (defect of Iris, retina, or optic disc • Heart disease (congenital) • Atresia of the choanae (nasal passage) • (Growth) Retardation • Genital defects • Ear anomolies

21. Crouzon Syndrome • Congenital • Conductive or Mixed Hearing loss • Other characteristics: • Prematurely fused cranial suture • Protrusion of eyes and beak-shaped nose • Variable outer/middle ear anomalies • Normal intelligence • Incidence with increased paternal age • 10q

22. Kippel-Feil Sequence • Congenital • Sensorineural and/or conductive hearing loss • Other characteristics: • Fused cervical vertebrae • Paralysis of VIth cranial nerve • Short Neck • Decreased head mobility • Ossicle abnormalities

23. Oseogenesis Imperfecta • Progressive • Sensorineural, conductive and/or mixed hearing loss • Other characteristics: • Fragile Bones • Large Skull • Hemorrhage tendency • Stapes fixation • 17q or 5p

24. Autosomal Recessive • Usher Syndrome • Goldenhar Syndrome • Hurler Syndrome • Pendred’s Syndrome • Alstrom Syndrome

25. Autosomal Recessive (Cont) • Frederick’s Ataxia • Fanconi Syndrome • Jervelland Lange-Nielsen Syndrome • Mobius’ Suyndrome

26. Usher Syndrome • Most common cause of profound hereditary deafness among children • Main cause of deaf-blindness • Congenital • Sensorineural • Three types

27. Usher I • Born with a complete, Profound hearing loss at all frequencies • Retinitis pigmentosa begins in early teens • Vestibular Dysfunction • Motor delays • Ia -- 14q • Ib & Ic -- 11q

28. Usher II • Born with moderate hearing loss in the low frequencies sloping to severe hearing loss in the high frequencies • Hearing loss progresses slightly over time • Progressive Retinitis pigmentosa • Occurs later in life and less severe than type 1 • Usually no vestibular problems • Iia -- 1q

29. Usher III • Rarest form of the disorder • Born with normal hearing and vision, and they progressively lose both senses • Mild hearing loss develops in early 20s and becomes progressively worse • Vision loss starts in young adulthood and becomes progressively worse • Most cases documented in Finland

30. Goldenhar Syndrome • Congenital • Unilateral of bilateral Conductive • Close relationship with Treacher Collins

31. Goldenhar Syndrome (Cont) • Other characteristics: • Facial asymmetry • Unilateral Microtiaand atresia • Preauricular tags • Eye anomalies • Oral defects • Club foot • Congenital heart disease • Abnormal semicircular canals • Mental retardation in 15% of cases

32. Goldenhar Syndrome (Cont)

33. Hurler Syndrome (Mucopolysaccaridosis I) • Progressive • Sensorineural, Conductive or Mixed • Skeletal deformities • Dwarfism • Coarse facial features • Corneal clouding • Cardiogvascular disorders • Mental retardation

34. Pendred Syndrome • May be autosomal dominant with incomplete penetrance and variable expression • Variable -- congenital or progressive • Sensorineural • Other characteristics: • Thyroid enlargement (goiter)

35. Alstrom Syndrome • Delayed onset; progressive • Sensorineural • Other characteristics: • Retinitis pigmentosa • Cataract • Diabetes mellitus • Obesity

36. Frederick’s Ataxia • Delayed onset; progressive • Sensorineural • Other characteristics: • Ataxia • Nystagmus • Optic atrophy

37. X-Linked Syndromes • Alport Syndrome (Types II, III, IV) • Hunter Syndrome

38. Alport Syndrome (Types II, III, IV) • Delayed onset; progressive • Sensorineural • Affects only males • Other characteristics (varies by type) • Renal disease • Ocular disorders • blood platelet defect • Xq

39. Hunter Syndrome • Similar to Hurler Syndrome, but may be less severe and affects only males • Progressive • Sensorineural, conductive, mixed

40. Hunter Syndrome (Cont) • Other characteristics: • Skeletal deformities • Dwarfism • Coarse facial features • Cardiovascular disorders • Mental retardation

41. Chromosomal Abnormalities • Down Syndrome (Trisomy 21) • Trisomy 13 • Trisomy 18