Carriers of Hemophilia: Carry the genes ,but not the stigma !


Shruti : Hey Riya,you have a secret admirer!! That Rahul, I have seen him look at you all the time with that silly “I am in love” smiling  face.

Riya : I don’t like all this nonsense Shruti,just shut up  and go

Shruti :Arrey,what happened? Chill!! I know you like him too.Don’t lie to me..

Riya : You know everything,why are you teasing me and messing with me??

Shruti : Because you are a dumbo. Riya, I talked to my cousin who is a doctor,she told me that you don’t have to worry at all.It is not as complicated as you think it is.You just overthink as always.
See, we are not even sure that you are a carrier, and even if you are, there are lots of options out there. There is solution for all your problems.
I know you are scared after hearing the bad experiences of a few.There are such jerks in this world,but majority are not like that.
Do not lock yourself in the tiny cage you have made for yourself.Just live the life !

A carrier is a person who carries the altered gene for Hemophilia,but does not have the condition.They can be Obligate carriers(who necessarily have the Hemophilia gene which they inherited from their father) or Possible carriers (who have the possibility of being a carrier ).

Obligate carriers include :

  • All daughters of a father with Hemophilia
  • Mothers of one son with Hemophilia and who have atleast one other family member with Hemophilia (brother, maternal grandfather, uncle,nephew or cousin)
  • Mothers of one son with Hemophilia and who have a family member who is a known carrier of the Hemophilia gene (mother,sister,maternal grandmother,aunt,niece or cousin)
  • Mothers of two or more sons with Hemophilia
Possible carriers include : 
  • All daughters of a carrier
  • Mothers of one son with Hemophiia who do not have  any other family members who have Hemophilia (or are carriers)
  • Sisters,mothers, maternal grandmother,aunts,nieces and female cousins of carriers
Should I test for carrier status ,and when ??
It is entirely the decision of you and your family to undergo the genetic testing and know if you are a carrier or not.
But,carriers may have a low level of factors and can be at risk of bleeding following trauma,tooth extraction,surgeries etc.Some have excess menstrual bleeding too.So,it is always better to have a Factor assay done in all possible carriers so that all the necessary precautions can be taken if the levels are found low.But remember,Factor levels do not confirm or negate your carrier status.
Also,there is no specific age to get the test done,many do it early so that the child gets enough time to get in terms with it gradually , and some wait until they are adults.However,it is always better to get the test done before a suspected carrier gets pregnant.
Tests for Identifying carriers 

  • Direct Mutation Testing 
           Many mutations cause Hemophilia.In this test ,we check for the specific mutation in your family.

For this test, the mutation of the male family member with Hemophilia have to be identified first using his blood sample. In about 98% cases, a mutation can be identified.Then, the  possible carrier female’s blood sample  is collected and her DNA checked for the specific mutation.
The results will be available only after  a few weeks.
Hence, the best idea would be to get the test done  well in advance ,before planning your pregnancy.

This is the most accurate test for identifying carriers.It is more expensive.

  • Linkage (Indirect) Testing
           In this method, the gene carrier status of the female is determined by tracking the gene in the family.Blood samples are collected from the possible carriers and from the male with Hemophilia and other family members.A comparison of the patterns of the linked DNA is made. The technicians check for the same pattern in DNA of the person with Hemophilia and in the DNA of family members.
This test is not as accurate as genetic testing.It does not provide information for all families.It can be done when a mutation cannot be identified.
  • Factor Assay
Carriers may have low levels of clotting factors.But,the levels do not confirm carrier status. The factor levels increase during pregnancy as a natural protective measure reaching the highest during the third trimester. Hence, checking your factor levels during pregnancy may not reveal the actual lower levels.
  • Pedigree or Family Tree
This is not a test to identify carriers.But,it is always advisable to draw a Family Tree or Pedigree.It generally includes three generations: Children,parents,aunts,uncles,cousins and grandparents.
It will help identify the possible carriers of Hemophilia
 
Why know your carrier status ?
It can provide valuable information to the women and their families regarding her Factor levels and also help manage her own health, help make wise reproductive decisions .It also helps to identify other possible carriers.
A symptomatic carrier should take precautions  while using over the counter drugs like Aspirin, and Non steroidal anti-inflammatory drugs that may interfere with normal clotting of blood.Also, she should be cautious about participating in contact sports and should always carry an appropriate medical identification with her.
If you are concerned about transmitting the Hemophilia gene to the coming generations, Pre natal diagnosis can help you.
Pre-natal diagnosis is  identifying Hemophilia in the foetus.It can be done by :
  • Chorionic villous sampling (CVS)
         It is an invasive procedure done between 11 weeks and 14 weeks of pregnancy.In this,a sample of the chorionic villi  cells from the placenta is obtained by inserting a fine needle through the abdomen  or by inserting a thin catheter through the mother’s vagina under local anaesthesia and ultrasonic guidance. The cells are then tested to identify the Hemophilia gene.
  • Amniocentesis 

This is another invasive procedure  which can be done between 15 weeks and 20 weeks of pregnancy.A fine needle is inserted into the uterus through the abdomen under ultrasonic guidance and a small amount of amniotic  fluid is collected. Amniotic fluid contains foetal cells.These cells are tested to identify Hemophilia.

 
Also, there are some conception options to eliminate the risk of having an affected child
  • In vitro fertilization (IVF) with pre-implantation diagnosis(PGD)
       This is quite an expensive procedure and not available at all centers.As in every IVF,it has only a 30% success rate per cycle.In this, the woman’s eggs are retrieved and fertilized with the sperms of her partner in a laboratory.The embryos are tested for the Hemophilia gene at a very early stage and only those without the altered gene are implanted into the mother’s womb.
However, a chorionic villous sampling/amniocentesis may still be needed for confirmation.
  • IVF with egg donation
          In this,donor eggs from a fertile woman who is not a carrier is fertilized with the sperms of the partner.The embryos are then implanted into the  mother’s womb
  • Sperm sorting
        This is still just a research tool and not readily available.In this,only sperms carrying an X chromosome is used thus ensuring birth of a female child. This cannot prevent birth of carrier females.
 
These are a few methods to prevent birth of a child with Hemophilia .You need not panic even if you have one.With the advent of better clotting factor concentrates and other treatment facilities, and governmental policies beneficial to the hemophiliacs, management of Hemophilia is getting better day by day. These information are shared here to keep yourself healthy and help you lead a good,happy life .

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