Is Holt Oram Syndrome hereditary?

Holt-Oram syndrome is a genetic condition that is hereditary, following an autosomal dominant inheritance pattern. This means that an affected individual has a 50% chance of passing the causative gene mutation to each of their children, regardless of the child's sex.

Is Holt-Oram syndrome hereditary?

Yes, Holt-Oram syndrome is a hereditary condition caused by mutations in the TBX5 gene. While it is hereditary—meaning it can be passed from parent to child—it is also a genetic condition that can occur spontaneously. Approximately 40% to 60% of cases are the result of de novo (new) mutations, meaning the individual is the first in their family to have the condition, with no prior family history.

How is the inheritance of Holt-Oram syndrome managed?

Because Holt-Oram syndrome follows an autosomal dominant pattern, even a small mutation in one copy of the TBX5 gene is sufficient to cause the syndrome. Genetic counseling is highly recommended for families to understand their specific risks. Clinical geneticists utilize molecular genetic testing to identify TBX5 variants, which can confirm a clinical diagnosis or assist in family planning.

What are the testing and prenatal options?

When a diagnosis of Holt-Oram syndrome is suspected, the following options are typically available to families:

• Diagnostic testing: Sequencing the TBX5 gene to confirm the presence of a pathogenic variant.


• Prenatal diagnosis: Available through CVS (chorionic villus sampling) or amniocentesis for pregnancies at known risk.


• Preimplantation Genetic Testing (PGT): Used during IVF to screen embryos for the familial TBX5 mutation.


• Cascade testing: Offering genetic screening to first-degree relatives of an individual diagnosed with Holt-Oram syndrome.

Next steps

• Consult with a board-certified clinical geneticist to discuss TBX5 testing.


• Connect with the 76 members of the Holt-Oram syndrome community at DiseaseMaps.org to share experiences.


• Schedule a cardiology evaluation, as Holt-Oram syndrome often involves structural heart defects that require specialized monitoring.

Medical disclaimer: This information is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Holt-Oram syndrome


• Orphanet: Holt-Oram syndrome (ORPHA:404)


• OMIM (Online Mendelian Inheritance in Man): #142900 (TBX5)


• GeneReviews: Holt-Oram Syndrome