<<Disclaimer: Verify this information before applying it to your situation.>>

Linda <[log in to unmask]> wrote:

>My sister is pregnant and would like to know if the baby has cd.  I
>recall cord blood testing being discussed some time ago.  ... although she
>will keep this baby gluten-free for 2 years, she would like to have the
>test done at birth.

I was probably the person whose post you recall.  My son's cord blood was
tested at birth, but not for CD itself.  CD is a condition which requires
gluten (and probably an additional environmental stimulus -- no one knows for
sure).  It would be theoretically interesting to do a biopsy on a newborn child
of an undiagnosed celiac mother.  I have never heard of this being done, but
from correspondence with celiac experts (I am NOT one myself), I suspect the
newborn would still not have active CD.

The test you can do at birth is a genetics test for HLA markers.  Over 95% of
all celiacs have a just 2 specific DR markers (compared to about 25% -30% of
the general population).  If the child has the same HLA type as his/her celiac
sibling, there is a 20%-40% chance of developing CD, depending on whether just
one or both chromosomes have the same HLA markers as the celiac sibling.

If the baby does not inherit the DR marker for celiac, it is extremely unlikely
he/she will ever get CD.  In the classic case where only one of the two parents
has a DR marker for celiac (and that parent does not have two copies of DR3),
then there is a 50%  chance the newborn will not inherit the celiac risk
profile.

We have an excellent reference file on the genetics of CD, written with the
generous assistance of Drs. Horvath and Sollid.  I urge everyone to read it,
and to have all your first degree relatives screened for CD with the endomysial
blood test, even if they do not have any symptoms.

Each first degree relative (parent, sibling, child) has roughly a 90% chance of
NOT having CD.  The joint probability that SOMEONE has CD can get fairly high.
For example, if a celiac has 2 parents, 4 siblings and 4 children, the
probability that at least one of them has CD should be about
1 - (0.9^10) =  65%.

To read the genetics file, either send an email to
[log in to unmask] with the body GET CEL-HLA, or tune your browser
to our web site: http://rdz.stjohns.edu/library/medic/celiac/index.html

Bill Elkus
Los Angeles