Hereditary factors account for about 50% of children with a moderate to profound hearing loss. Genetic counseling and genetic testing to determine the cause of a child's hearing loss and to supply information for the family is important for management of health problems which may accompany hearing loss.
Genetic information is useful because some syndromes associated with deafness may have other health issues. For example, a deaf child with Usher syndrome may develop retinitis pigmentosa causing night blindness; Pendred syndrome is associated with a goiter; BOR syndrome or Melnick-Frase syndrome may cause ear pits, cysts in the neck and kidney anomalies; Waarenburg syndrome may be associated with heterochromia (eyes with different colors), white forelock of hair, and wide spaced eyes; and Alport syndrome may result in progressive kidney disease. Jervell Lange-Nielsen (JLN) syndrome is another example of a condition that emphasizs benefits of genetic testing. Children with JLN syndrome may develop heart disease and a prolonged QT interval on EKG reading. Thus, there are many genetic diseases with or without associated findings which may cause hearing loss with or without a positive family history.
Therefore, early detection of a hearing loss in a child who inherited a syndromic form of hearing loss provides an opportunity to prevent or control other symptoms related to the hearing loss. The vast majority of inherited types of hearing loss are not associated with a syndrome(1) of other health problems but a careful analysis of the family history and clinical examination may be needed. Some parents may also benefit from genetic counseling in understanding the possibilities of hearing loss in future children or their risk of inheritance of genetic conditions in which hearing loss is a feature.
Identificatioin of a gene that is responsible for hearing loss in a child will provide a more accurate diagnosisfor the type of hearing loss and its inheritance pattern. Such knowledge may help to improve management of hearing loss for the patient and allow screening for other family members.
One center that performs genetic testing for deafness is at Boys Town National Research Hospital in Omaha, Nebraska.
Boys Town National Research Hospital
Locations in Missouri that provide genetic testing and counseling can be located by contacting:
The American Society of Human Genetics 9650 Rockville Pike Bethesda, Maryland 20814-3998 (301) 571-1825The American Society of Human Genetics
References:
(1) "Genetic Counseling for Hearing Loss", Kathleen Arnos, The Volta Review, Vol. 99(5)