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.
You can wear hearing aids behind your ear, in your outer ear, in your ear canal , or completely implanted in the ear. The kind of hearing aid you choose depends on many things, including your degree of hearing loss, your doctor or audiologist's advice, and what kind of hearing aid you want. See a picture of different styles of external hearing aids .