Multiple Hereditary Exostoses Information

Introduction

Multiple Hereditary Exostoses produces bone deformities, shortened stature, bony growths, limb length discrepancies, and tumors. Symptoms also include difficulty moving joints, loss of motion, and fatigue. MHE can stretch or compress nerves, causing motor and sensory difficulties and pain; irritating muscles and tendons, and creating severe fatigue in the person afflicted. The tumors associated with MHE can cause an array of additional issues.

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Defining Multiple Hereditary Exostoses

Multiple Hereditary Exostoses (MHE) is a disorder marked by tumors which are benign that cap bones and grow out-wards from areas of the growth plate of long bones, or from the surfaces of flat bones. MHE is also referred to by additional names such as, 'Osteochondromatosis,' 'Cartilaginous Exostoses,' Hereditary Multiple Osteochondromata,' Diaphyseal Aclasis,' and others. The, 'Exostoses,' are either Pendunculated, or Sessile. Pendunculated tumors have a, 'pedicle,' which arises from the cortex; commonly directing away from the growth of the plate of the bone. Sessile tumors present a more broad-based attachment to the cortex of the bone.

Wheeless' Textbook of Orthopedics states that fifty percent of persons with MHE present with a forearm deformity, while forty-five percent have a form of ankle deformity. Forty percent of persons with MHE have a shortened stature due to the disorder, and twenty percent have a knee deformity. Discrepancies in limb length, as well as wrist and hand deformities are also common.

Transmission

The transmission of MHE is described as being in an, 'Autosomal Dominant,' manner. What this means is that if one parent has MHE there is a fifty percent chance that any children they have will also develop the disorder. Spontaneous mutation is responsible for approximately ten percent of the cases of MHE.

Symptoms

MHE produces bone deformities, shortened stature, bony growths, limb length discrepancies, and tumors. Symptoms also include difficulty moving joints, loss of motion, and fatigue. MHE can stretch or compress nerves, causing motor and sensory difficulties and pain; irritating muscles and tendons, and creating severe fatigue in the person afflicted. The tumors associated with MHE can cause an array of additional issues.

Perhaps the most serious complication of MHE is the potential for an exostosis to become malignant, degenerate, and become a Chondrosarcoma. People who notice that an exostoses is growing larger and more painful after they have stopped growing should see their doctor. Exostoses pain and growth are two potential signs that a benign tumor may have become a malignant one, and needs intervention. Persons who develop malignant chondrosarcomas are usually in their twenties to their fifties.

On occasion, an exostoses which develops on the ribs may cause difficulty with breathing in a person. On rare occasion pelvic exostoses might cause either intestinal or urinary obstructions. For persons with MHE who experience these forms of exostoses, the only forms of treatment include surgical intervention, physical therapy, occupational therapy, and pain management.

Treatment

Medical science has not found a cure for MHE, although scientists continue to search for one. Surgical interventions are possible, and vary. One surgery involves removing a troublesome tumor which might be either pressing on a nerve or interfering with the person's growth. The surgeon staples the person's growth plate in the ankle, knee, or wrist in order to stop the limb from bowing. They may also lengthen the person's leg or arm using a, 'Fixator.' After an exostoses has been removed there is a twenty to fifty percent chance that it may grow back, but it may not regrow to a large enough size to cause symptoms. Sometimes tumors are able to be removed without the person even staying overnight in the hospital.

There is a chance that if an exostoses is causing an abnormality in growth, removing it early enough may allow the affected bone to straighten itself out as a child continues to grow. In other cases, the exostoses must be removed, and the bone straightened as well. This involves either cutting the bone and straightening it and holding it in place as it heals, or changing the rate of growth on one side of the growth plate in a developing child.

One of the risks persons with MHE face through surgery is a nerve disorder known as, 'Sympathetic Dystrophy Syndrome,' (RSD) which can be very painful. There are other complications which may develop from surgical intervention for MHE, such as nerve palsy, or potential staph infection.

There are also persons with MHE who never require treatment. They compensate for things such as decreased range of motion or deformity, and continue to function. As deformity occurs, it may happen at a rate that is very slow, allowing them to compensate for it.

Causes

The genes responsible for the disorder are EXT1 and EXT2. Medical science suspects that EXT3 may also be involved, but have yet to prove it. Chromosomes numbers eight, eleven and nineteen have been shown as locations where genetic information related to MHE comes from. There are some researchers who believe that there may be different types of MHE, each one caused by different types of genes in these locations.

Living With Multiple Hereditary Exostoses

Daily tasks such as walking, sitting, sleeping, writing, and additional things can be very difficult for persons with MHE. Tumors which press on tendons, muscles, nerves and other bones in the body can be very painful, making everyday living a challenge. Tasks that may seem simple to others, such as putting on their socks and shoes, become difficult for persons with MHE.

Being touched by others in areas where tumors are pressing on sensitive areas of the body can be painful for persons with MHE. Lying down to sleep at night necessitates the use of things like feather beds, extra blankets, padding or even pressure-relieving mattresses. Some persons with MHE use adaptive equipment like wheelchairs because walking is too painful.

Research

Scientists in different nations have shown that the genes connected with MHE are found on three different chromosomes, leading to the belief that MHE is caused by at least three separate genes with one or more on each chromosome. Each of the genes is located on chromosomes numbers eight, eleven and nineteen; chromosome eight is the most common location found. Continued research, and the insight provided by this information, gives scientists information into the growth of cells, and may lead to treatment for MHE. Gene mapping studies may serve as a basis for testing children who are risk for MHE.

Author Credentials:

Thomas C. Weiss is a researcher and editor for Disabled World. Thomas attended college and university courses earning a Masters, Bachelors and two Associate degrees, as well as pursing Disability Studies. As a Nursing Assistant Thomas has assisted people from a variety of racial, religious, gender, class, and age groups by providing care for people with all forms of disabilities from Multiple Sclerosis to Parkinson's; para and quadriplegia to Spina Bifida. Explore Thomas' complete biography for comprehensive insights into his background, expertise, and accomplishments.

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Cite This Page (APA): Weiss, T. C. (2009, January 23 - Last revised: 2017, June 25). Multiple Hereditary Exostoses Information. Disabled World. Retrieved October 10, 2024 from www.disabled-world.com/health/orthopedics/multiple-hereditary-exostoses.php

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