What Is GJB2-Related DFNB1 Nonsyndromic Hearing Loss and Deafness? DFNB1 nonsyndromic hearing loss and deafness is an inherited condition in which an individual has mild to severe hearing loss, usually, from birth. It is caused by mutations in GJB2 (which encodes the protein connexin 26) and GJB6 (which encodes connexin 30). The condition does not typically worsen over time, but in some cases may be slowly progressive. The word “nonsyndromic” refers to the fact that there are no other symptoms or systems of the body involved with the disease. Unlike some other forms of hearing loss, DFNB1 nonsyndromic hearing loss and deafness does not affect balance or movement. The degree of hearing loss is difficult to predict based on which genetic mutation one has. Even if members of the same family are affected by DFNB1 nonsyndromic hearing loss and deafness, the degree of hearing loss may vary among them. How Common Is GJB2-Related DFNB1 Nonsyndromic Hearing Loss and Deafness? In the United States, the United Kingdom, France, Australia, and New Zealand, approximately 14 in 100,000 individuals have DFNB1 nonsyndromic hearing loss and deafness. This may be an underestimate as individuals with a mild presentation may not be diagnosed. Roughly 1 in 33 Caucasian individuals are carriers a the mutation that causes the condition. While this condition is most recognized in the Caucasian population, it has also been observed in other ethnicities. How Is GJB2-Related DFNB1 Nonsyndromic Hearing Loss and Deafness Treated? Individuals with DFNB1 nonsyndromic hearing loss and deafness may show improvement by using hearing aids. For those with profound deafness, cochlear implants may also be helpful. They may also want to consider enrolling in an educational program for the hearing impaired. What is the Prognosis for an Individual with GJB2-Related DFNB1 Nonsyndromic Hearing Loss and Deafness? While an individual with GJB2-related DFNB1 nonsyndromic hearing loss and deafness will have mild to severe hearing loss, it does not affect lifespan and does not affect any other part of the body. Other names forGJB2-related DFNB1 nonsyndromic hearing loss and deafness Autosomal recessive deafness 1 DFNB1 DFNB1 nonsyndromic hearing loss and deafness GJB2-related DFNB1 nonsyndromic hearing loss and deafness Neurosensory nonsyndromic recessive deafness 1 References Chan et al., 2014, Laryngoscope, 124(2):E34-53, PMID: 23900770 Kenneson et al., 2002, Genet Med, 4(4):258-74, PMID: 12172392 OMIM: Online Mendelian Inheritance in Man, OMIM [220290], 2016, https://www.omim.org/entry/220290 Smith et al., 2016, https://www.ncbi.nlm.nih.gov/books/NBK1272/ Wingard et al., 2015, Front Cell Neurosci, 9:202, PMID: 26074771