23andMe Updated Report for People with Asian Ancestry

23andMe updated its report on an inherited condition characterized by mild to profound hearing loss. The update to 23andMe’s Nonsyndomic Hearing Loss and Deafness, DFNB1 (GJB1-Related) Carrier Status Report adds six variants that improve the coverage of the test for people with East Asian, Southeast Asian, and South Asian ancestry.

“We are extremely excited about this report update, which allows us to provide new and meaningful genetic information to tens of thousands of our customers,” said 23andMe Product Scientist Ruth Tennen. “This is one step forward in our efforts to make our health reports more equitable, and to work toward a in which people of all ancestries can access, understand, and benefit from the human genome.”

The National Library of Medicine  describes a clinical description of Nonsyndromic hearing loss and deafness (DFNB1). It is characterized by a congenital (present at birth) non-progressive sensorineural hearing impairment. Intrafamilial variability in the degree of deafness is seen.

Except for hearing impairment, affected individuals are healthy; life span is normal.

23andMe says the drive behind their update of carrier status was to add variants that would make the report more relevant to people of diverse ancestries. Because being a carrier for DFNB1 is quite common in people of East Asian and Southeast Asian descent, 23andMe prioritized adding variants that are commonly found in those populations. 

With the addition of the new variants, up to 15 percent of 23andMe’s East Asian and Southeast Asian customers will receive an update indicating that they have a variant detected. More than 1 percent of 23andMe’s South Asian customers will receive a similar update. In total, more than 100,000 Health + Ancestry Service customers across all ancestries will receive an updated report with a new variant detected.

This form of nonsyndromic hearing loss and deafness, or DFNB1, is characterized by mild to profound hearing loss that is typically present from birth. The condition is caused by variants in a gene called GJB2, which contains instructions for a protein that helps transport potassium ions and other molecules between cells. Because proper movement of potassium ions in the inner ear is needed for the brain to process sound, variants that disrupt the function of GJB2 gene can cause hearing loss.

The condition is autosomal recessive, which means that a person must inherit two GJB2 variants – one from their mom and one from their dad – in order to have the condition. People with just one GJB1 variant are called carriers. They’re not expected to have the condition themselves, but they could pass their variant on to their future children. If two carriers have children, there’s a 25 percent chance that each child may have DFNB1. DFNB1i is the most common form autosomal recessive nonsyndromic hearing loss, accounting for half of all cases.

In its recent update, 23andMe added 6 new variants to the Nonsyndromic Hearing Loss and Deafness, DFNBI (GJB2-Related) Carrier Status report. These additional variants include some that are particularly common in people of East Asian, Southeast Asian, and South Asian descent. 

The newly added variants are also frequently found in people of Ashkenazi Jewish, European, Ghanaian, and Hispanic/Latino descent. The previous version of the report included two variants that are most common in people of Ashkenazi Jewish and European descent.

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