Rare Bone Disorders

There are many health conditions that affect very few people in the world. These diseases and disorders are very rare to observe and are scattered cases around the world. Most of these conditions are genetic and there is very little information available about their treatment.

In many cases there is nothing known about their causes. This is because there are not many patients suffering from these conditions for scientists to study the causes and possible treatments in detail. Most of these rare diseases that affect bones have no cure and are very difficult to diagnose.

The following list contains names and information in short about some of the really rarely diagnosed conditions that affect the bones. Read on and learn about these bone disorders.

Also known as monostotic fibrous dysplasia, this is a form of fibrous dysplasia. This condition involves just one bone in the body. This is a rare bone disorder that causes swelling, pain and bone deformities. People suffering from this disorder are very prone to bone fractures.

Craniodiaphyseal dysplasia (CDD) is an autosomal recessive bone disorder. This is an extremely rare condition where the calcium builds up in the skull. This causes disfiguring of the facial features of the affected person.

The calcium buildup in the skull pushes the eyes towards the edges of the head. The nose gets twisted out of shape and the person loses his eyesight and hearing ability eventually. This condition reduces the life expectancy of the patients tremendously. There have been less than 20 cases reported with CDD till date.

This is an extremely rare inherited bone disorder. This condition is also known as marble bone disease and Albers-Schonberg disease. This condition causes the bones to harden and become more brittle than normal.

In milder forms the condition causes no symptoms or problems in the affected person. However, in severe cases it leads to deformity, stunted growth, etc. It can be treated by a bone marrow transplant, only if the osteiclasts are affected.

The term SADDAN is an acronym for severe achondroplasia with developmental delay and acanthosis nigricans. This is a rare inherited bone disorder that affects the growth of the skeleton, brain and the skin. People suffering from this disorder have extremely short arms and legs.

They suffer from bow legs, a short chest, curved collar bones, broad and very short fingers. They suffer from mental retardation, seizures and developmental delays. Children suffering from SADDAN may develop acanthosis nigricans. This is a progressive skin disorder that causes the skin to become thick, velvety and dark in color.

Spondyloepiphyseal dysplasia congenita (SED) is an extremely rare bone growth disorder. It leads to dwarfism in the affected person. This condition is characterized by skeletal abnormalities, that is present from birth. The person displays a short trunk, neck and limbs. The height of an adult with this condition is about 0.9 meters to around 1.4 meters.

Köhler disease affects children between the age of 6 to 9 years. In the condition, the blood supply to the navicular bone of the foot is lost. This causes the bone to die and collapse. Children start walking with a limp and may complain of pain in the foot.

Treatment of Köhler disease includes resting the affected foot. Pain relievers are given and in some cases, the foot is placed in a cast. Once the navicular bone becomes normal, the condition resolves to a great extent. Typically, within 2 years, the condition seems to improve with proper treatment.

This is an extremely rare inherited disorder that causes the person to develop very short hands and feet. These people also suffer from growth retardation, delayed bone maturation as well as facial abnormalities. This condition tends to have no known cause and is said to occur sporadically.

The Sakati-Nyhan-Tisdale syndrome is also known as the acrocephalopolysyndactyly type III condition. This is a rare genetic disorder that causes abnormalities of the bones in the legs, carniofacial defects as well as congenital heart defects. The cause of this condition is unknown reasons and is said to be a sporadic genetic mutation.

Roberts syndrome is one of the rarest autosomal recessive disorders that occurs due to a genetic mutation of ESCO2 gene present on the 8th chromosome. This condition is characterized by severe prenatal retardation, malformation of the bones of the skull, face, arms as well as legs.

This condition requires equal copies of the genes from both parents to take effect. The rate of mortality of this condition is very high in affected individuals.

The TAR syndrome, that is, Thrombocytopenia with an Absent radius is a very rare genetic disorder. This condition leads to absence of the radius bone present in the forearm. The person also suffers from massive reduction in the number of platelets in the blood, leading to thrombocytopenia. Treatment includes platelet transfusions and a surgery to help normalize the appearance of the arm.

These disorders affect less than 0.5% people around the world. As they are very rare, not much research or studies have been conducted related to these disorders.