Genetics and Deafness: Implications for Education and Life Care of Students with Hearing Loss

Jerome D. Schein, PhD, is professor emeritus of sensory rehabilitation at New York University and adjunct professor of psychology at the University of Alberta (Canada). Maurice H. Miller, PhD, is adjunct professor emeritus of audiology/speech language pathology at New York University, former chair of the Communications Disorders Advisory Committee for the NYC Department of Health, and a member of HR’s editorial advisory board. Details and references related to this article can be found in the authors’ 2008 book, Hearing Disorders Handbook (www.pluralpublishing.com).

Editor’s Note: This article was adapted from a 2008 paper¹ by the authors that appeared in the American Annals of the Deaf, and provides a follow-up to a related article² by the authors published in the August 2008 HR. It appears here with permission.

The severity of deafness can obscure the presence of other disabilities that may accompany genetic anomalies, such as occur in Alport and Usher syndromes. Recent advances in genetics have heightened attention to various disabilities and dysfunctions that may coexist with deafness. Failure to recognize these additional disabilities when they occur can misguide educational planning; may open the afflicted deaf person to failure to identify, diagnose, and manage potentially serious health conditions; and in some instances may even lead to loss of life. Of the many genetic conditions that have been identified, a few examples are cited to illustrate the need to inform parents, educators, and other caregivers about the importance of obtaining genetic information.

Deafness can so dominate the attention of practitioners that they may overlook other disabilities that might accompany it. Research has found that an estimated 1 of 3 deaf schoolchildren has an educationally or physically disabling condition.³

Some of these additional disabilities are genetically linked to deafness. Their presence will go unrecognized unless the diagnostician is alert to the potential for the existence of such syndromes. Although the present article focuses solely on genetic conditions that include multiple disabilities, those that include deafness and other conditions that result from illnesses and accidents also deserve consideration.

The Importance of Diagnostic Scrutiny

Advances in genetic research have increased attention to syndromes and spectra that include both deafness and other disabilities. Some of these conditions may not manifest themselves until late in childhood or in adulthood. While some of these conditions are well known, others have only recently been identified.⁴ All are relevant to the care of deaf children and young deaf adults.

Knowing that additional physical problems may coexist with deafness should enable parents, as well as educators, audiologists, and other professionals who have a responsibility for deaf children, to avoid serious consequences that may occur if the additional conditions are overlooked. A good rule to follow is:

Whenever deafness is identified, search for additional physical disabilities.

Adopting such diagnostic scrutiny can be justified by the overwhelming impact of deafness, which often obscures the possibility of other physical problems.

In this article, we consider some of the organ system pathologies that have been found along with auditory dysfunction to affect deaf persons. However, the syndromes and spectra we discuss represent only a sample of the range of conditions that include an additional disability with deafness. At least 60 syndromes have been identified that include deafness and other severe dysfunctions.⁴

Authors’ Note: We use the term “deafness” throughout the remainder of the present article, even though in some instances “hearing loss” would be more appropriate. We hope, nonetheless, that use of the broader term improves readability without loss of either clarity or pertinence.

Ophthalmic Disorders

Contrary to popular notions that deafness is compensated by greater visual ability or acuity, the most common defects associated with deafness are ophthalmic. On average, deaf people tend to have visual defects at a greater rate than their age-group counterparts in the general population.^3,5

Usher syndrome is the best known and probably the most frequently occurring single coincidence of auditory and vision symptoms.^6,7 In its commonest form, the deafness is present at birth and the vision loss develops slowly, usually up to the third decade of life, though variations abound. An ophthalmologist can usually make the diagnosis of Usher syndrome in a deaf child of about age 5. Such early diagnosis can lead to treatment that anticipates the additional vision loss, prepares the child for what lies ahead, and enables the educational counselor to direct education toward occupations that will be suitable for a deaf-blind person.

Another much rarer condition is Goldenhar syndrome, which is also known as keratitis-ichthyosis-deafness (KID) syndrome. As in Usher syndrome, the visual loss in KID syndrome is progressive, typically culminating in blindness. Of special value in the treatment of KID and Usher syndromes is providing early amplification and, when appropriate, a cochlear implant, along with counseling to prepare the child for the later onset of blindness.

Two other syndromes that include auditory and ocular conditions are Refsum syndrome⁸ and Alstrom syndrome.⁹ For more conditions that combine auditory and vision losses, see Miller and Schein.⁴

Kidney Dysfunctions

Several genetic syndromes include kidney (renal) dysfunctions with deafness. The most prevalent of these is Alport syndrome.¹⁰ Its presence is made known by an often-subtle symptom: blood in the urine (hematuria). The amount of blood may be so small that it is dismissed as inconsequential. However, in a person who is deaf, the symptom may indicate Alport syndrome.

When a person with Alport syndrome is subjected to a stress, such as surgery, kidney failure may occur. If the surgeon in charge of the operation does not anticipate such a possibility and does not make provisions to manage it, death may result. In later adulthood, persons with Alport syndrome usually develop end-stage renal disease, requiring kidney dialysis. Despite such treatment, the disease may still prove fatal.

Two other conditions involving both deafness and kidney dysfunction should be mentioned here. One has the descriptive name hypoparathyroidism deafness renal dysplasia (HDR) syndrome. HDR syndrome may include mental retardation, seizures, syncope, and other neurological symptoms along with the deafness and renal dysfunction.¹¹ Its full-blown nature may not be revealed until late childhood or early adolescence, so HDR syndrome should be identified as early as possible, principally by DNA analysis, to avoid delaying treatments and precautionary measures that can prevent more serious consequences.

The other deafness-renal syndrome is branchio-oto-renal (BOR) syndrome. It is rare, occurring in about 1 of every 40,000 live births. Like persons with Alport and HDR syndromes, those with BOR syndrome must carefully manage their renal health throughout their lives.¹²

Heart Conditions

Several syndromes involve cardiovascular conditions and deafness. Identifying these syndromes may be critical to saving a deaf person’s life. Such a situation arises when the deaf person has a fainting spell.

Syncope (temporary loss of consciousness caused by a fall in blood pressure) is not unusual, especially among teenage girls; however, if the cause is Jervell and Lange-Nielsen (JLN) syndrome, the resulting cardiac arrhythmia can be fatal.¹³ An electrocardiogram (EKG) can reveal a pattern readily identified by cardiologists. When it arises in a deaf person, it signals JLN syndrome. Knowing that a deaf person suffers from JLN syndrome should alert caregivers to the need to seek emergency assistance if that person faints.

Because fainting spells can occur without warning, and because cases of JLN syndrome do not display obvious symptoms of the cardiac defect, all deaf children should have an EKG—a relatively inexpensive, noninvasive procedure with a high probability of uncovering the presence of the syndrome.

Several other genetic conditions also include deafness and cardiac conditions. Among these are CHARGE association¹⁴ and Stickler syndrome, also known as Pierre-Robin sequence.¹⁵ Altogether, these inherited conditions argue strongly for a cardiologist and a geneticist to examine all children with congenital hearing loss.

Summary and Conclusions

By highlighting a handful of all the possible genetic conditions that involve both deafness and other serious disorders, we aim in this article to sensitize caregivers to the necessity for intensive and extensive physical examinations of all children with hearing loss. Such diagnostic procedures should include careful genetic studies, not only of the child but also of parents and other family members—even those who show no signs of hearing loss or other disability—if they are amenable to being analyzed genetically. Such analysis may identify those who, though they themselves are not affected, are carriers of an aberrant gene.

Recent improvements in medical and genetic diagnoses can assist parents and educators of hearing-impaired children in management of these children’s futures. The increased awareness of syndromes and spectra that include other disabilities and dysfunctions with deafness and hearing loss should redound to the benefit of the children who may be affected by such genetic conditions and for whom failure to identify the genetic condition would represent missed opportunities to better, if not to save, their lives. In any event, knowledge of present or anticipated additional disabilities that may accompany hearing loss can assist these students, their parents, and the educators responsible for them in making suitable curriculum choices and in adopting realistic career and life planning.

The above discussion makes obvious the need to inform parents of children with hearing loss about these possible multiple conditions. Furthermore, we recommend introducing a segment on multiple disabilities in the curricula preparing special educators and administrators of programs for hearing-impaired students. (Less certain is whether making such information a part of curricula for deaf students or informing their parents and caregivers is sufficient.) Such portions of a curriculum need not be lengthy to be effective in sensitizing educators and other caregivers to the value of thorough diagnostic procedures that include genetic analyses. Informing them about the possibility that deafness or hearing loss may be accompanied by other disabilities can contribute to their competence and to the welfare of these children.

Acknowledgements

This article was originally published in the American Annals of the Deaf (see Schein and Miller1 below). The authors and HR thank Donald Moores, editor of the Annals, and Dan Wallace, assistant director of Gallaudet University Press, for their generous assistance in republishing this article.

References

1. Schein JD, Miller MH. Genetics and deafness: implications for education and life care of deaf students. Am Ann Deaf. 2008;153(4):408-410.
2. Schein JD, Miller MH. Deafness and death. Hearing Review. 2008;15(9):12-14.
3. Schein JD, Miller MH. Diagnosis and rehabilitation of auditory disorders. In: Kotke JF, Lehman JF, eds. Krusen’s Handbook of Physical Medicine and Rehabilitation. 4th ed. Philadelphia: Saunders; 1990:935–966.
4. Miller MH, Schein JD. Hearing Disorders Handbook. San Diego: Plural Publishers; 2008.
5. Schein JD. Deaf students with other disabilities. Am Ann Deaf. 1975;120:92-99.
6. Kimberling WJ. Usher syndrome. Available at: www.boystownhospital.org/research/molecularstudies/Pages/UsherSyndrome.aspx. Accessed March 16, 2010.
7. Wolf EG, Schein JD, Delk MT. Needs Assessment of Services to Deaf-blind Individuals. Washington, DC: Rehabilitation and Education Experts (REDEX); 1982.
8. Horoupian D. Pathology of the central auditory pathways and cochlear nerve. In: Alberti PW, Ruben RJ, eds. Otologic Medicine and Surgery. New York: Churchill Livingstone; 1988:713–734.
9. Welsh IW. Alstrom syndrome: progressive deafness and blindness. Ann Otol Rhinol, Laryngol. 2007;116(4):281-285.
10. Barker DF, Pruchno CJ, Jiang K. A mutation causing Alport syndrome with tardive hearing loss is common in the western United States. Am J Hum Genetics. 1996;58(6):1157-1165.
11. Asif A, Christie PT, Grigorieva IV. Functional characterization of GATA3 mutations causing the hypoparathyroidism deafness-renal dysplasia (HDR) syndrome: insight into mechanisms of DNA binding by the GATA3 transcription factor. Hum Molec Genetics. 2007;16(3):265-275.
12. Bodurtha J, Nance WE. Genetics of hearing loss. In: Alberti PW, Ruben RJ, eds. Otologic Medicine and Surgery. New York: Churchill Livingstone; 1988:851-853.
13. Jervell A, Lange-Nielsen F. Congenital deaf-mutism, functional heart disease with prolongation of Q-T interval, and sudden death. Am Heart J. 1957;54:59-68.
14. Edwards BM, Kileny PR, Van Riper LA. CHARGE syndrome: a window of opportunity for audiologic intervention. Pediatrics. 2002;110(1):119–126.
15. Soulier M, Sigaudy S, Chan C. Prenatal diagnosis of Pierre-Robin sequence as part of Stickler syndrome. Prenatal Diagnosis. 2002;22(7):567-568.

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