What are the other Names for this Condition? (Also known as/Synonyms)

• Autosomal Dominant Brachyolmia
• Brachyrachia

What is Brachyolmia Type 3? (Definition/Background Information)

• Brachyolmia Type 3, or Autosomal Dominant Brachyolmia, is a relatively severe form of brachyolmia, a group of rare genetic skeletal disorders, characterized by short-trunked short stature, platyspondyly and kyphoscoliosis. Degenerative joint disease (osteoarthropathy) in the spine, large joints and interphalangeal joints becomes manifest in adulthood
• Patients with Brachyolmia Type 3 generally have a normal birth weight and length. Affected individuals present with moderately short trunk/short stature and mildly short limbs in childhood
• Kyphoscoliosis is common and sometimes severe. Adult patients develop degenerative joint disease in the spine, large joints and small joints of the hands and feet, which may cause significant musculoskeletal morbidity, such as chronic pain in the extremities and spine, and paresthesia. Final adult height is reported to be 155-168 cm (males) and 136-150 cm (females)
• The radiographic features include severe platyspondyly particularly in the cervical spine, elongated vertebral bodies (overfaced pedicles), broad ilia, and mild metaphyseal irregularity in the proximal femora. Carpal ossification may be mildly delayed, and mild brachydactyly may exist

(Source: Autosomal dominant brachyolmia; Orphanet, National Institute of Health and Medical Research (INSERM), Paris.)

Who gets Brachyolmia Type 3? (Age and Sex Distribution)

• Brachyolmia Type 3 is a rare congenital disorder; only 30 cases are reported in the scientific literature
• The presentation of symptoms may begin in childhood, with severe manifestations taking place during adulthood
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Brachyolmia Type 3? (Predisposing Factors)

• A positive family history may be an important risk factor, since Brachyolmia Type 3 can be inherited
• Currently, no other risk factors have been clearly identified for the disorder

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Brachyolmia Type 3? (Etiology)

Brachyolmia Type 3 is caused by mutation(s) in the TRPV4 gene located on chromosome 12.

• The TRPV4 gene codes for a calcium-permeable cation channel, which is involved in regulation of osmotic sensitivity as well as mechanical stimuli
• TRPV4 gene mutations are inherited in an autosomal dominant manner

Autosomal dominant: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition or pass it on to their offspring.

What are the Signs and Symptoms of Brachyolmia Type 3?

The signs and symptoms of Brachyolmia Type 3 may include:

• Abnormality of the metaphysis
• Barrel-shaped chest
• Childhood-onset short-trunk short stature
• Clinodactyly
• Hypermetropia
• Kyphosis
• Proximal femoral metaphyseal irregularity
• Radial deviation of finger
• Increased vertebral height
• Kyphoscoliosis
• Platyspondyly
• Short stature
• Short thorax
• Short femoral neck
• Short neck
• Spinal cord compression

(Source: Brachyolmia Type 3; Genetic and Rare Diseases Information Center (GARD) of National Center for Advancing Translational Sciences (NCATS), USA.)

How is Brachyolmia Type 3 Diagnosed?

Brachyolmia Type 3 is diagnosed on the basis of the following information:

• Complete physical examination
• Thorough medical history evaluation
• Assessment of signs and symptoms
• Laboratory tests
• Imaging studies
• Biopsy studies, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Brachyolmia Type 3?

The complications of Brachyolmia Type 3 may include:

• Severe back pain due to kyphoscoliosis
• Difficulty with movement, due to degeneration of bones in joints
• Pulmonary hypertension
• Heart abnormalities due to ribcage pressing against the chest organs
• Low self-esteem due to inability to reach full normal height and other physical disabilities

Complications may occur with or without treatment, and in some cases, due to treatment also.

How is Brachyolmia Type 3 Treated?

• There is no cure for Brachyolmia Type 3, since it is a genetic condition. The treatment is usually given to manage the signs and symptoms and any complication that develop
• Severe curvature in the spine due to kyphoscoliosis may necessitate surgical corrections

How can Brachyolmia Type 3 be Prevented?

Brachyolmia Type 3 may not be preventable, since it is a genetic disorder.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders
• Regular medical screening at periodic intervals with tests and physical examinations are recommended

What is the Prognosis of Brachyolmia Type 3? (Outcomes/Resolutions)

• The prognosis of Brachyolmia Type 3 is dependent upon the severity of the signs and symptoms and associated complications, if any
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications
• Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information:

The following DoveMed website link is a useful resource for additional information:

http://www.dovemed.com/diseases-conditions/rare-disorders/