More than 24,000 children are born with hearing loss in the United States each year. Boys Town National Research Hospital is a national leader in the diagnosis and treatment of children with moderate to profound hearing loss.

Information on Hearing Loss - Genetics and Deafness -
Branchio-Oto-Renal (BOR) Syndrome

Branchio Oto Renal Syndrome (BOR) is a genetic disorder that includes malformations of the ear and cysts in the neck, hearing loss, and malformations of the kidney. BOR has an autosomal dominant mode of inheritance. This means that for an individual who has BOR, there is a 50% chance of passing on the gene with each pregnancy. Nonpenetrance (having no sign or symptom of the disorder despite having the gene) is very unusual for BOR. However, variable expression (variation in the manner and severity with which the gene is expressed among and within families) is very common, and an individual with the gene may have only one or two of the three clinical aspects of the syndrome.

The B in BOR refers to the branchial arches which is the area of the embryo that develops into the outer and middle ear, the neck and the lower part of the baby's face. There are several types of malformations of the branchial arches in BOR including cupping of the outer ear, ear pits which are very small holes (about the size of the hole in a pierced ear) in front of or on the outer ear, tags of skin in front of the ear, and cysts or fistulas on the neck.

Oto refers to the ear and in particular the hearing loss that is part of the syndrome. The hearing loss can be sensorineural, conductive or mixed. It can be stable or progressive and the severity can range from mild to profound. Most people with BOR have some degree of hearing loss.

Renal refers to the kidneys which can be abnormal in size, shape and/or structure. They may be smaller than usual or have a malformation that does not interfere with function or cause any symptoms. However, the kidney malformation may be severe enough to predispose the individual to kidney disease, or a baby may be born without kidneys which would be incompatible with life. Most people with BOR do not experience any type of kidney problem.

In some families with BOR there are individuals who have blocked tear ducts which interfere with the normal flow of tears and have to be opened surgically. There have also been reports of individuals with salivary tissue in their tear ducts which causes them to have tearing when they eat.

For more information on the genetics of BOR, see http://www.medicine.uiowa.edu/pendredandbor/borBackground.htm.

For additional information and resources on BOR, see http://www.thecainfoundation.com.

For more information about our research, or to participate, contact: Maren Jensen, Research Assistant to William J. Kimberling, PhD Boys Town National Research Hospital Genetics Department 555 N. 30th St. Omaha, NE 68131

Phone: (402) 498-6344
Toll-free: (800) 835-1468
FAX: (402) 498-6331
E-mail: jensenml@boystown.org