Detailed Description
Nonsyndromic hearing loss and deafness (DFNB1) is a genetic disorder characterized by mild to severe hearing loss at birth. It is caused by structural and functional alterations in the connexin 26 protein involved in potassium ion transport.
Connexins are proteins that form channels,called gap junctions, between cells. These channels allow the transport of molecules (such as potassium ions) between cells. People with DFNB1 produce a non-functional connexin 26 protein, which disrupts the structure and/or function of gap junctions, leading to hearing loss.
Take this test to find out if you are a genetic carrier for DFNB1 and are at risk of passing a variant to your children.
![](https://www.dnaaccesslab.com/wp-content/uploads/sites/112/DFNB1_3-2.jpg)
The Genetics
DFNB1 is caused by genetic variation in the GJB2 gene. This gene provides instructions for the connexin 26 protein. Connexin proteins form channels (gap junctions) between cells that are required for transport of molecules. Disrupting the function of connexin 26 protein, affects the function of gap junctions, which inhibits potassium ion recycling and leads to hearing loss.
DFNB1 is inherited in an autosomal recessive manner, which means two defective copies of the GJB2 gene need to be inherited in order for hearing loss to manifest.
![](https://www.dnaaccesslab.com/wp-content/uploads/sites/112/DFNB1_2.jpg)
Variants Tested
This test detects two variants in the GJB2 gene that are the most common causes of DFNB1 in people of Ashkenazi Jewish descent (93% of carriers) or European descent (85% of carriers).
- rs80338939
- rs80338942
Understanding your carrier status for these variants will help you understand the risk of passing a variant to your children.
How It Works
Step 1: Sign up for a free DNA Access account.
Step 2: Upload your DNA markers to DNA Access.
Step 3: Log in to your account to access your results when they are ready.