Inner radial bundle formation is then mediated by Eph/Ephrin signaling, which is a target of Pou3f4 transcription factor activity (21,22).
Variants in the POU3F4 gene at the locus DFN3 are a major cause of X-linked deafness worldwide.
From a clinical perspective, when POU3F4 is identified as the HL-causing gene, the surgeon should be alert for a perilymphatic gusher during stapes surgery.
HRCT and MRI findings in X-linked non-syndromic deafness patients with a POU3F4 mutation.
X-linked deafness-2 (DFNX2) phenotype associated with a paracentric inversion upstream of POU3F4. Am J Audiol 2014;23:1-6.
Background: The molecular genetic research showed the association between X-linked hearing loss and mutations in POU3F4. This research aimed to identify a POU3F4 mutation in a nonsyndromic X-linked recessive hearing loss family.
So far, five loci (DFNX1, DFNX2, DFNX3, DFNX4, and DFNX6) and four genes ( PRPS1 , POU3F4 , SMPX , and COL4A6 ) have been found for X-linked hearing impairment.[sup] The clinical features of DFNX3 comprise profound mixed hearing loss and vestibular problems in males.[sup]
The molecular genetic research showed the association between X-linked hearing loss and mutations in POU3F4 .[sup] This gene belongs to a superfamily of POU domain transcription factors (transcription factor 4 of the POU domain, Class III), which encodes transcription factor with bipartite DNA-binding domains, a 75-amino acid POU-specific domain that is linked by 17 amino acids to a 63-amino acid homeobox domain.
There are 52 variants reported in the Human Gene Mutation Database, including intragenic mutations, complete or partial deletions, duplications, inversions, and other chromosomal deletions.[sup] To identify the mutation in the POU3F4 gene, in this study, we performed the analysis in a Chinese nonsyndromic X-linked hereditary hearing loss family.
X-Linked Nonsyndromic Hearing Loss Loci Characteristics Locus/Location Gene Name Onset/Decade Type DFN1/Xq22 DDP Postlinqual/1st Progressive DFN2/Xq22 -- Prelingual Stable DFN3/Xq21.1 POU3F4
Prelingual Stable DFN4/Xq21.2 -- Prelingual Stable DFN5/pending -- -- -- DFN6/Xq22 -- Postlinqual/1st Progressive Table 4.