Biology Reference
In-Depth Information
syndromic hearing loss have been determined by linkage analysis (Mueller,
Van Camp, and Lench, Chapter 4). Testing for most of these genes is now
available on a research basis and, for some, on a clinical basis.
Genetic testing may be appropriate in a variety of situations and for
several reasons. When a syndromic form of deafness is suspected, genetic
testing may be able to confirm or rule out a particular syndrome. Hearing
parents with one or more deaf children may be interested in testing to iden-
tify the cause of deafness in these children. Subsequently, they may want to
know about their options for carrier testing for their hearing children and
prenatal diagnosis for future pregnancies. When both members of a couple
have nonsyndromic autosomal-recessive deafness, they may desire testing
to find out whether their chances to have deaf children are near 0% or
100%.
It is important for the genetic counselor to be aware of and be prepared
to discuss appropriate clinical tests and research protocols with families.
For clinical testing, genetic counselors should be able to explain what type
of sample is needed and how much, the cost of the test, and the turn-around
time for results. In evaluating a research protocol, genetic counselors should
know the inclusion criteria for a study and be able to answer families' ques-
tions, such as: “What does participation require of me?” “Is there any cost
to me?” and “Will I get results from the study?” It is also critical that genetic
counselors be involved in conveying the results of testing to the family. A
person who receives the results of genetic testing may have many questions
regarding carrier testing for other members of the family, reproductive
options, and treatment. The identification of a specific form of hereditary
deafness may also be a very emotional time for the person or the family. It
is important that a genetic counselor be the primary point of contact or
part of a team of individuals responsible for providing this information to
the family.
3.7 Discussion of Diagnosis, Inheritance Pattern,
Prognosis, and Treatment Options
During a genetic counseling session or sessions following the genetic eval-
uation, the individual or family will be given complete information regard-
ing the diagnosis, mode of inheritance, prognosis, reproductive implications,
treatment options, options for prenatal diagnosis, and other recommended
options for support or follow-up. Particular attention is paid to providing
this information in a manner that is sensitive to the individual's needs and
the emotional state of the individual or family. The decision-making process
regarding reproductive and treatment options for hereditary deafness may
be strongly influenced by the cultural identification and psychosocial needs
of hearing parents of a deaf child or deaf adults who identify with the Deaf
community. In the non-directive and supportive atmosphere provided by
a sensitive and responsive genetic counselor, individuals or families are
