Hereditary bone disease includes a number of skeletal system disorders caused by a family disposition. Problems causing weak, fragile, or deformed bones can arise from the bone itself, or from organs such as the kidney, liver, intestine, or parathyroid gland. Some hereditary bone diseases are rare, while others are relatively common. Most of these diseases share the symptoms of bone pain, and frequent fractures.
Hypophosphatasia
Hypophosphatasia is an inherited disease that alters the normal incorporation of calcium into the bones and teeth. The National Institutes of Health Genetics Home Reference page reports that about 1 in 100,000 newborns are affected by severe hypophosphatasia, and milder forms of the disease probably occur more often. The condition can begin in the womb, during childhood, or in early adulthood. The earlier the onset of the illness, the more severe its effects.
Hypophosphatasia causes the bones to be soft and weak. Infants with the disorder have soft skulls, short limbs, and a malformed chest. Adults usually experience bone pain from multiple fractures in the legs and feet. A mild form of the disease spares the bones and only affects the teeth, causing abnormal tooth structure and early tooth loss.
Hereditary Multiple Exostoses
Hereditary multiple exostoses (HME) is a disorder where bony growths, called exostoses or osteochondromas, form along the long bones. These growths result in short stature, and deformities. The arms and legs may grow in an asymmetrical fashion, producing limbs of differing lengths. People with this disease often suffer from a limited range of motion, and arthritic problems. The bony growths develop throughout childhood, but stop once full height is reached. About 1 in 50,000 people have HME.
Achondroplasia
Achondroplasia is a type of short-limbed dwarfism, and is the most common form of the dwarfism. While this is a hereditary condition, most cases arise from a mutation wherein neither parent carries the gene, according to MedlinePlus.com. Achondroplasia involves an inability of the body to change cartilage into bone. People with this condition have a disproportionately large head, and a prominent forehead. They have a short stature, and short limbs. As adults, they often develop a sway back and bow legs, making it painful and difficult to walk. Short-limbed dwarfism occurs in 1 in each 15,000 to 40,000 people.
