Holt-Oram syndrome
Holt-Oram syndrome Causes
Mutations in the TBX5 gene lead to Holt-Oram syndrome. The TBX5 gene plays a role in the growth of the heart and upper limbs before birth. In particular, this gene appears to be important for the process that divides the growing heart into four chambers (cardiac septation). The TBX5 gene also appears to play a critical role in controlling the development of bones in the arm and hand. Mutations in this gene probably hinder the development of the heart and upper limbs, leading to the characteristic features of Holt-Oram syndrome.
Holt-Oram syndrome Definition
Holt-Oram syndrome is a disorder that affects bones in the arms and hands and may also cause heart problems in patients.
Holt-Oram syndrome Diagnosis
Holt-Oram syndrome is congenital, so diagnosis may be made based on hand and arm abnormalities. If the hand/arm abnormalities are subtle, the diagnosis may not be made until later on in life, when the heart symptoms of the disease become evident. X-rays can recognize bone abnormalities, and an electrocardiogram or echocardiogram can detect heart problems.
Holt-Oram syndrome Symptoms and Signs
Defects in the bones of the hand and/or arm are always evident. They may affect either or both sides of the body. Typically, there are defects in the carpal bones of the wrist and in the bones of the thumb. The thumb may be misshapen or even absent. In some severe cases of Holt-Oram syndrome, the arms may be very short in length so that the hands are attached close to the body (called phocomelia).
Holt-Oram syndrome Treatment
Treatment of Holt-Oram syndrome is concetrated on treating the symptoms. Large heart defects can result to heart failure, so a cardiologist will need to be consulted. Children with severe arm defects can be referred to orthopedic surgeons to help improve arm function.