Related Match

[Jo P]

I am a 6/6 match for my 7 year old son. Is anyone aware of any 6/6 matches for mother / child matches? Thanks.

[Neil Cuadra]

That's great news, Jo, and great insurance in case your son needs a transplant. Since he got half his chromosomes from each parent that means that you and your husband have HLA types (genes) in common. It's strictly determined by inheritance over the generations.

Parent/child matches are fairly uncommon but it's much more likely when parents are from the same ethnic background and have ancestors from a population that tends toward more homogeneity and less genetic diversity, for example if your families have both been in Australia for many generations. Matches are also more likely if your genes and your husband's genes are more common in the gene pool. A single rare gene makes a match much less likely.

In you're interested in more detail here's an explanation that might help. Six-of-six matching is based on antigens named A, B, and DR, which comes in sets. For example, using made-up numbers, you and your husband might have these HLA combinations:

A1 B2 DR3 -- you got from your mother
A4 B5 DR6 -- you got from your father
A7 B8 DR9 -- your husband got from his mother
A1 B2 DR3 -- your husband got from his father <-- by chance matches one set you have

The matching sets of you and your husband aren't enough. Your son would have only a 1/4 chance of inheriting that combination. It was equally likely that he'd get

A1 B2 DR3 from you and A7 B8 DR9 from your husband
A1 B2 DR3 from you and A1 B2 DR3 from your husband
A4 B5 DR6 from you and A7 B8 DR9 from your husband
A4 B5 DR6 from you and A1 B2 DR3 from your husband <--- match with you

So you were lucky to share typing with your husband and lucky again that your son inherited the right combination. The testing center might be willing to share your HLA typing results so can see the real data. They did that for us when my family members were typed, although in our case we didn't have a match.

No matter which factors led to the match it's a bit like winning the lottery - a long-shot chance over which you didn't have control but for which you're very happy to use the winnings!

[tserdogan]

Hi Jo,
My mom had been my donor,2 years from post transplant.if you have question,please write to me...

[Neil Cuadra]

tserdogan,

How good a match were you and your mom?

[tserdogan]

Hi Neil,
6/6 with my mom.Two thing was handicap for me.My mom was over 65 year old,and three child.
i get red blood transfusions 9 months post transplant.i had not gvh problems.
Near two years has passed from transplant my blood counts are raising slowly to normal counts.i had some complaints about nerve paralysis(eyes and voice),and i am not still gaining my body balance.
Jo,
How old are you?i don't think your age is over 45.and this is avantage for you.

[squirrellypoo]

Are the transplant team planning on during further matching? I only ask because when they were looking for my unrelated donor, they first found 8 broad matches for me, who were then all called back in for further samples, which were then compared to mine at 10 points. Two of these were 9/10 matches for me, but sometimes a mismatch at one point is better than a mismatch at another, which is how they finally decided on my donor.

I'm used to seeing donors described as x out of 10, though - it seems strange they only checked at 6 points for you...? A 6 out of 10 is usually not considered good enough for transplant, so you'd think they'd want to test further to see if you're 6 or higher.

[Neil Cuadra]

For a 6-point match they test the A, B, and DR markers. For a 10-point match they also test the C and DQ markers.

A 6/6 match from an unrelated donor might be turn out to be 6/10, 7/10, 8/10, 9/10, or 10/10 after further testing. But I suspect that a 6/6 match with a parent or sibling has a much higher probability of turning out to be a full 10/10 match.

[Jo P]

After tissue typing our Dr explained that my husband and I have 2 common antigens, but that my son ended up with the 2 common ones, plus 4 of mine due to a cross-over. Our Dr said that she has only seen one other parent / child match (but in the US) not in Australia.
My son has had ATG in late December 2010 and was going reasonably well although his platelets starting dropping and then he ended up in hospital twice with infections during April. His levels have dropped further over the past 4 weeks.

I am 40 and have had 3 children. My son with SAA is the youngest.
Thanks for your information.

[squirrellypoo]

Originally Posted by Neil Cuadra

But I suspect that a 6/6 match with a parent or sibling has a much higher probability of turning out to be a full 10/10 match.

Originally Posted by Jo P

After tissue typing our Dr explained that my husband and I have 2 common antigens, but that my son ended up with the 2 common ones, plus 4 of mine due to a cross-over.

Ahhhh! These two points together have made the genetics click in my brain now! Thanks, it makes sense now... Though I can definitely see why parent/child matches are so very rare!

[Gokcen]

My mother will have Haploidentical SCT at 1st september, 6/4 match donor, my youngest sister.