The Vel weak phenotype is due to a heterozygous deletion in the same exon, resulting one functional copy of the SMIM1 gene. If a patient who is Vel negative is transfused with Vel positive red blood cells, they may form anti-Vel alloantibodies.
Hearing aids need to be fitted by someone trained specifically in hearing problems. An audiologist or licensed hearing aid provider can make sure your hearing aids fit and work for your type and degree of hearing loss. You also need to consider cost.
While hearing aids can be helpful for most people with hearing loss, there are some for whom hearing aids either do not help or help insufficiently. In such cases, cochlear implants can be helpful and are being used by more people with severe and profound hearing loss who no longer benefit from hearing aids.