Beukes familial hip dysplasia

Alternate names

BFHD; Hip dysplasia Beukes type; Osteoarthropathy, premature degenerative, of hip; Cilliers-Beighton syndrome

Definition

Beukes hip dysplasia (BHD) is a rare inherited skeletal dysplasia affecting the hip joint.

Summary

• In general, skeletal dysplasias are a group of disorders which affect the bone and cartilage.
• Skeletal dysplasias are more commonly known as types of dwarfism, but not all skeletal dysplasias cause a person to be short in height.
• In fact, BHD only affects the hip joint.

Epidemiology

As of 2015, BHD has only been found in relatives of a single family in South Africa who were of European descent. BHD has affected many generations and members of this family. Family members with BHD now live in other parts of the world as well.

Cause

• Beukes hip dysplasia (BHD) is caused by a change or mutation in one copy of the UFSP2 gene.
• Genes come in pairs (one copy from each parent) and are the blueprints or code for making proteins .
• Since only one copy of the UFSP2 gene is mutated, some normal UFSP2 protein is made using the other copy of the gene, just not enough.
• Now that the gene which causes BHD is known, medical researchers are studying how the decreased amount of the UFSP2 protein causes the degeneration of the hip joint.

Inheritance

Autosomal dominant pattern, a 50/50 chance.

• Beukes hip dysplasia (BHD) is inherited (runs in families) in an autosomal dominant manner. This means that having a change (mutation ) in only one copy of the responsible gene in each cell is enough to cause the symptoms of the condition. However, not everyone who inherits the mutation in the UFSP2 gene develops problems in their hip joint. This called incomplete penetrance. About 80% of the people who inherit the mutation in the UFSP2 gene will develop symptoms of BHD.
• When a person with a mutation that causes an autosomal dominant condition has children, each child has a 50% (1 in 2) chance to inherit that mutation. But since the condition has incomplete penetrance and there is a range in severity of symptoms, it is difficult to predict how the mutation in the UFSP2 gene will affect a person's life.

Onset

Symptoms of hip joint pain and discomfort usually begin in infancy or later childhood, but may also begin as late as the mid-30s.

Signs and symptoms

In fact, BHD only affects the hip joint. A person with BHD is similar in height to other family members. There are no other health problems associated with BHD. Beukes hip dysplasia (BHD) causes severe progressive degenerative osteoarthritis of the hip joint in early adulthood. Severity of the condition varies even among family members. In fact some people who inherit the change or mutation in the gene which causes BHD never develop any problems with their hip joint. After symptoms begin, the characteristic signs of secondary osteoarthritis (including bone sclerosis, cyst formation and narrowing of the joint space) develop and the joint deteriorates rapidly.

For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. 80%-99% of people have these symptoms

• Abnormal ossification involving the femoral head and neck
• Abnormality of bone mineral density
• Abnormality of the epiphysis of the femoral head(Abnormality of the end part of the innermost thighbone)
• Broad femoral neck
• Hip dysplasia
• Osteoarthritis(Degenerative joint disease)

5%-29% of people have these symptoms

• Coxa vara
• Kyphosis(Hunched back)
• Scoliosis

Diagnosis

• The predicted amino acid substitution inactivates UFSP2 proteolytic function, thus implicating the ubiquitin-fold modifier 1 cascade in this form of severe hip osteoarthropathy.
• The facile polymerase chain reaction-based assay we describe could be used to confirm the diagnosis of BHD, or for presymptomatic testing of members of the extended BHD family.

Treatment

Treatment depends on the severity of symptoms, but may include walking aids (such as a cane or walker), medication for pain or to reduce inflammation, and/or hip joint replacement surgery.

NIH genetic and rare disease info

• NIH info on Beukes familial hip dysplasia

Beukes familial hip dysplasia is a rare disease.