Anatomical variation of the posterior septal artery leads to refractory epistaxis.

Purpose: To report a rare variant of the posterior septal artery (PSA), which supplies blood to the posterior mucosa of the contralateral nasal septum. Case report: A 31-year-old female patient underwent suture removal 14 days after septoplasty and developed left-sided epistaxis 6 h after suture removal. To safely and effectively relieve the patient from epistaxis, the cauterization of the left PSA was performed under general anesthesia. However, 24 h after the first surgical hemostasis, the patient experienced epistaxis again in the right nasal cavity. We have reviewed the patient's sinus computed tomography again and found a rare variant of PSA, which is the right-sided PSA passing through a bony canal in the left-sided nasal septum. Discussion: The variant of PSA well explained the failure of the first hemostatic surgery. Therefore, we again performed a cauterization of the right-sided PSA, after which the patient recovered and no further epistaxis occurred. Conclusion: When cauterization of PSA is used to manage posterior epistaxis, it is necessary to pay attention to the possible variation in PSA.

Mutation of SLC7A14 causes auditory neuropathy and retinitis pigmentosa mediated by lysosomal dysfunction.

Lysosomes contribute to cellular homeostasis via processes including macromolecule degradation, nutrient sensing, and autophagy. Defective proteins related to lysosomal macromolecule catabolism are known to cause a range of lysosomal storage diseases; however, it is unclear whether mutations in proteins involved in homeostatic nutrient sensing mechanisms cause syndromic sensory disease. Here, we show that SLC7A14, a transporter protein mediating lysosomal uptake of cationic amino acids, is evolutionarily conserved in vertebrate mechanosensory hair cells and highly expressed in lysosomes of mammalian cochlear inner hair cells (IHCs) and retinal photoreceptors. Autosomal recessive mutation of SLC7A14 caused loss of IHCs and photoreceptors, leading to presynaptic auditory neuropathy and retinitis pigmentosa in mice and humans. Loss-of-function mutation altered protein trafficking and increased basal autophagy, leading to progressive cell degeneration. This study implicates autophagy-lysosomal dysfunction in syndromic hearing and vision loss in mice and humans.