rs80338950
This is a variant in the GJB2 gene that changes a arginine to an glutamine.
▶ClinVar annotation
Autosomal dominant nonsyndromic hearing loss 3A; Autosomal recessive nonsyndromic hearing loss 1A (DFNB1A); Hearing impairment; Hearing loss; Nonsyndromic genetic hearing loss; Rare genetic deafness; not specified
View on ClinVar →▶Research that mentions this SNP (4)
▶GJB2: The spectrum of deafness-causing allele variants and their phenotypeAssociationN=1,294Azaiez H. et al.(2004)· Human Mutation
This study characterizes the spectrum of GJB2 (Connexin 26) mutations causing DFNB1 autosomal recessive deafness in 1,294 deaf individuals. Among 205 DFNB1 cases identified, the c.35delG deletion accounts for most alleles, with homozygotes showing 88% mean hearing impairment and severe-to-profound deafness in ~90% of cases, while individuals with two missense mutations show only 37% mean impairment (P<0.05). The study also identified non-coding mutations including c.1-3172G>A and del(GJB6-D13S1830), and validated DHPLC as a highly sensitive (98.1%) mutation screening method.
▶Frequencies ofGJB2mutations in German control individuals and patients showing sporadic non-syndromic hearing impairmentReviewSusan Kupka et al.(2002)· Human Mutation
This comprehensive review examines genetic analysis methods for otorhinolaryngeal (ENT) diseases, covering both monogenic disorders with simple Mendelian inheritance (hereditary deafness, otosclerosis, Kallmann syndrome) and complex multifactorial diseases. The paper emphasizes diagnostic approaches including differential, predictive, and prenatal diagnosis, discusses inheritance patterns and genetic counseling requirements, and reviews specific ENT-related genetic conditions including syndromal and non-syndromal hearing impairments, hereditary tumors (neurofibromatosis type 2, paragangliomas), and hereditary syndromes (Waardenburg, BOR, CHARGE, Treacher-Collins).
▶Carrier Rates in the Midwestern United States for <EMPH TYPE="ITAL">GJB2</EMPH> Mutations Causing Inherited DeafnessAssociationN=612Green GE et al.(1999)· JAMA
This study determined the carrier frequency of GJB2 mutations causing inherited deafness in the Midwestern United States. Of 52 probands with congenital sensorineural hearing loss, 22 (42%) had GJB2 mutations, with the 35delG mutation accounting for 29 of 41 mutant alleles. The 35delG carrier rate was 2.5% (SE 0.66%) in 560 control neonates, and the overall carrier rate for all GJB2 deafness-causing mutations was 3.01% (range 2.54-3.56%), with a calculated sensitivity and specificity for 35delG screening of 96.9% and 97.4% respectively.
▶AssociationN=141Unknown
This study sequenced the connexin 26 gene (GJB2) in Japanese patients and identified three novel mutations (235delC, 176-191del(16), and Y136X) responsible for prelingual deafness. The 235delC mutation was most frequent (7 of 10 mutant alleles) with a carrier frequency of 2/203 (approximately 1%) in the normal Japanese population, indicating GJB2 mutations account for ~12% of prelingual deafness in Japan.
About GJB2
This gene encodes a member of the gap junction protein family. The gap junctions were first characterized by electron microscopy as regionally specialized structures on plasma membranes of contacting adherent cells. These structures were shown to consist of cell-to-cell channels that facilitate the transfer of ions and small molecules between cells. The gap junction proteins, also known as connexins, purified from fractions of enriched gap junctions from different tissues differ. According to sequence similarities at the nucleotide and amino acid levels, the gap junction proteins are divided into two categories, alpha and beta. Mutations in this gene are responsible for as much as 50% of pre-lingual, recessive deafness. [provided by RefSeq, Oct 2008]
View all GJB2 variants →Gene information from NCBI Gene. Variant classifications from ClinVar.
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