Research has shown that a variation in the gene called GJB2 increases a baby’s chance of hearing loss. Learn more here.
Research has shown that a variation in the gene called
GJB2 increases a baby’s chance of
hearing loss. The GJB2 gene contains the instructions for a protein, Connexin
26, that plays an important role in the development and functioning of
the cochlea. There are many different variations in this gene that can cause a
hearing loss. About 40% of the newborns with hearing loss, who do not have a
syndrome, have a variation in the GJB2 gene, according to a report issued by
the CDC’s Early Hearing Detection & Intervention (EHDI) Program.
Every person
has two copies of the GJB2 gene, one from each of their parents. However, a
person with two variant copies of the gene, one variant copy inherited from
each parent, will have hearing loss. So if both parents have a variant copy of
the gene, they can have a child with hearing loss, even though both parents can
hear. In fact, 90% of babies with hearing loss are born to parents who can
hear.There is a commercially available test for Connexin defects that is
used to aid in genetic counseling for people with a suspected hereditary
hearing loss.
To read more about the genetics of infant
hearing loss, click here to access the EHDI site.You will also
find a wealth of other informative materials, including a Parent's Guide to Genetics booklet and Promenade 'round the Cochlea , containing information about how the ear works,
interesting pictures and graphics.