Pediatric Genetic Counseling in Practice

Genetic Condition: Hemophilia (Factor IX Deficiency)

 

Historical Figure: Tsarevich Alexis Romanov (1904 – 1918)

 

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What would have happened if Tsarevich Alexis was born in the 21st century?

A 1 month old baby boy, is brought to the emergency room by his parents, Tsar Nikolas the II (the last Tsar of Russia) and Tsarina Alix, for uncontrolled bleeding from his belly button. Thankfully, the nurses and doctors were able to get the bleeding under control, and baby Alexis did not need a blood transfusion. A blood clotting disorder is suspected, so the emergency room staff page the genetics unit within the hospital. A genetic counselor and geneticist come and visit the baby and his family.

 

What does the genetic counselor do?

  • Take a detailed pregnancy and medical history for Alexis and his mother:

Tsarina Alix had no complications while she was pregnant, but bled a little longer that woman usually do after the birth of Alexis. She shared that this also happened during the births of her older children, four daughters. Other than this episode, Alexis does not have any other health problems.

  • Take a detailed family history:

Alexis has four older sisters, and none of them have any health problems. Alexis’ Uncle Fred (Alix’s brother) died at the 3 years old after he fell and hit his head. The injury caused a bleed in his brain that could not be stopped. Alexis’ cousin Waldemar also bled to death at the age of 4. As Tsarina Alix talks about her family, the genetic counselor draws a family tree, known as a pedigree:

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  • The genetic counselor and geneticist notice that it is almost only males in the family that have bleeding problems. This is consistent with a genetic condition carried on the X chromosome, known as X-linked recessive.
  • The geneticist than does a physical exam of Alexis, looking for bruising (an indicator of internal bleeding), and any physical features that babies with different genetic disorders have.
  • The geneticist and genetic counselor order blood tests to look at how well Alexis’ blood clots.

 

The blood clotting tests come back and show that Alexis’ blood clots very poorly and that he has very low levels of Factor IX, an important protein to help blood clot when you cut or injure yourself. There are a few different things that can cause someone to have low levels of Factor IX, including some medications and liver disease. But, looking at Alexis’ family, the genetic counselor and geneticist are highly suspicious of a genetic disorder called Hemophilia B (Factor IX deficiency).

 

The genetic counselor:

  • Explains Alexis’ blood clotting test results to his parents, and explains why they think Alexis has Hemophilia B
  • Describes the genetic testing that can find out if Alexis has Hemophilia B
  • Talks about the symptoms of Hemophilia B, and how bleeding episodes can be treated by giving children injections of Factor IX

 

The testing is ordered and the results come back. Alexis has a mutation in the gene causing Hemophilia B.

 The genetic counselor (and usually the geneticist as well) will:

  • Share the results with the parents
  • Comfort and support the parents, as they adjust to this news
  • Talk about what medical problems Alexis is expected to have through his life with Hemophilia B, and which specialists he will see to help keep him healthy
  • Discuss what treatment is available for Alexis to help him with his bleeding problems
  • Educate the parents about how the gene mutation is likely being passed down in the family, and who is at risk of medical problems or to have children with the disease
  • Give the family information about organizations for Hemophilia and how to meet other families with a Hemophilia diagnosis