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Some questions to the groups of
Geneticists who are working on Joubert Syndrome answers
from the university of Washington
Dr. Philip chance, MD offices by Melissa Parisi, md, PhD
Oct 9, 2003
Hi Everyone:
In response to some questions that some members had
regarding the scientists, collaboration and a recent new
publications for another mutation being discovered, I
sent some questions to the 2 groups of Geneticists that
are working on Joubert Syndrome. The responses below are
from the Seattle group. I want to make mention that the
University if Washington group in Seattle responded very
quickly and promptly to my request for answers to these
questions.
Cheryl Duquette, President and Co-Founder
Joubert Syndrome Foundation & Related Cerebellar
Disorders
6931 South Carlinda Ave.
Columbia, MD 21046
410-997-8084 fax: 410-992-9184
email:
joubertduquette@comcast.net
Joubert Syndrome Foundation (JSF) Question: What
does the University of Washington research group (headed
by Dr. Philip Chance) think of the recent publications
in the American Journal of Human Genetics?
Melissa Parisi MD., PhD (MP) Answer: We assume
you are referring to the recent publication by 2
separate research groups, one of which was headed by Dr.
Joe Gleeson at the University of California in San
Diego, and the other of which was by an Italian group.
These publications announced the identification of a
second locus for a Joubert gene on chromosome 11. This
is a very interesting and potentially very exciting
development, and we hope that this will lead to new
insights into the genetic causes of Joubert Syndrome.
We would like to point out that this new "locus" (or
genetic location) for Joubert syndrome represents a
large region of genetic material (millions of base pairs
of genetic information) and that the specific
disease-associated gene has not yet been identified. In
fact, there may be several hundred different genes
within this locus on chromosome 11. The task of
identifying a specific gene may take years. The first
locus identified for Joubert syndrome on chromosome 9
was first published in 1999, and the gene has not yet
been found. Unfortunately, the pace of progress in
genetic research is sometimes slower than we would like.
And even when a gene is discovered, it does not always
lead directly to a treatment or a cure for the
condition.
Since the publication of the chromosome 11 locus, we
have examined markers in this region in samples from
many of our families, and our data suggest that the
majority of families are not likely to be linked to this
region. This implies that the Joubert gene in most of
the families that we have under study from the U.S. is
not located on chromosome 11. Previous studies in our
laboratory have also excluded the chromosome 9 locus in
the majority of our families. Nevertheless, we will
continue to examine chromosome 11 and other chromosome
regions in order to find Joubert genes. We anticipate
that there are likely to be many genes for Joubert
syndrome (perhaps 5-10). Therefore, this finding should
spur increased efforts to find ALL of the genetic causes
of Joubert syndrome, but does not provide the final
answer to our quest.
JSF Question: Are the University of Washington
team and Dr. Joe Gleeson’s group working together or
separately on the genetic studies?
We have worked with Dr. Gleeson's laboratory on genetic
studies of Joubert syndrome in the past, and we have
shared approximately 50 patient samples with his
research group. It has always been our goal to pursue
this research jointly, but it has been difficult to
develop collaborative agreements. In the spring of this
year, our group developed a very specific collaborative
agreement which was presented to a group of interested
laboratories, including Dr. Gleeson's group.
Unfortunately, this agreement was ultimately rejected.
We have continued to work with many researchers in the
Joubert syndrome field, including Dr. Dobyns, Dr. Maria,
Dr. Koenig, Drs. Andermann, and Dr. Dostal. We welcome
collaborations and we believe that a combined effort
will be most beneficial for success in future projects.
JSF Question: If we have previously sent blood to
Dr. Chance’s group at the University of Washington, may
we also want to send to Dr. Gleeson’s group in San
Diego?
MP Answer: Families are always welcome to send
blood to whomever they choose. However, the policy at
the University of Washington has been to recommend
sampling an individual only once, with the assumption
that those samples are precious and should be shared
appropriately. We believe that establishing permanent
cell lines on each sample we receive is the best way to
ensure that there is enough material for distribution
among collaborators, so that there is no need to
resample children (or adults) if the initial DNA sample
runs out. We have been constructing cell lines since we
began this research in the early 1990's, and although it
is a more expensive and labor-intensive process, we
believe the samples deserve this level of commitment.
We would like to remind families that progress in
medical research is measured in slow, incremental, and
sustained efforts. It is very common for contributions
to be made by other researchers who may have been
fortunate to find a large, inbred family to study.
However, we would caution families that it is not
necessary or useful to send blood to every lab that
publishes a research paper on Joubert syndrome. Once a
gene location is published, other researchers in the
field can also work on that region. A discovery such as
the chromosome 11 locus is just the
first step in the difficult task of finding the gene, a
task which is often shared by many research groups. Our
group is committed to the efforts to find Joubert genes,
and has been collecting samples for over ten years. We
are in this for the long-haul and will diligently
follow-up on all discoveries in the Joubert research
field, whether they are made by our group or by other
groups.
As we stated earlier, we believe that collaborations
between laboratories and sharing samples is a very
desirable goal. We have reciprocally shared samples in
the past with Dr. Gleeson, and with other laboratories.
Unfortunately, collaboration between our group and the
Gleeson group is limited at this time, and will remain
limited until we are able to resolve some serious
issues. We hope that this will be rectified in the
future.
Families should not be overly discouraged to learn that
all of the laboratories are not necessarily
collaborating with each other, because it is clear that
progress is being made, and we expect the pace of
discovery to accelerate. The fact is, competition is
usually good for stimulating research activity and new
discoveries.
We want to reassure families that when each gene for
Joubert syndrome is found, we will look for mutations in
the patient samples we have collected. In all
likelihood, there will be several different research
groups who discover Joubert genes, and we intend to be
one of them.
We appreciate the faith that families have placed in our
efforts to find Joubert genes and learn more about this
condition, and we look forward to continuing our work
with the families and the Joubert Syndrome Foundation.
We are committed to the mission of the JSF and want to
help make discoveries that will have a positive impact
on children with this condition. Together we can get the
work done!
Thank you for allowing us to answer your questions.
Further information on our research is available at our
website:
http://joubertsyndrome.washington.edu.
Please contact Melissa Parisi MD., PhD if you have
additional questions (mparisi@u.washington.edu).
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for information only and should not be considered as medical
advice. Please always consult your physician for medical
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