Chromosome 12: Holt-Oram Syndrome

Bri Whalen

What is Holt- Oram Syndrome?

Abnormalities in skeletal development gives presentation of deformed limbs (arms and hands).

This syndrome also severally affects the cardiovascular system, particularly the shape or beat of the heart.

This syndrome affects approximately 1 out of every 100,000 births.

What causes Holt-Oram Syndrome?

• As an autosomal dominant trait, it is genetically inherited by only one of the parents with the mutated gene; unlike most inherited dominant genes that need to come from both parents.

• Mutations in the TBX5 gene on chromosome 12 cause Holt-Oram Syndrome.

What’s the TBX5 gene?

When it is functioning properly, the TBX5 gene provides the instructions for making tissues and organs when the embryo is still developing during pregnancy.

When it is mutated, tissues and organs (in particular, the heart and upper limbs) develop abnormally—this is Holt-Oram Syndrome.

How can Holt-Oram Syndrome be treated?

Treatment of Holt-Oram syndrome goes on a case-by-case basis, given different severities of the syndrome.

Typically a team of different specialty doctors (cardiologists, geneticists, orthopedic surgeons, etc.) is assembled to monitor and treat patients.

References

http://ghr.nlm.nih.gov/condition/holt-oram-syndrome

http://rarediseases.info.nih.gov/gard/6666/holt-oram-syndrome/resources/9

http://www.nlm.nih.gov/medlineplus/ency/article/002049.htm

http://emedicine.medscape.com/article/159911-overview#a0104