| |
 |
Focus on Prenatal Diagnosis at the
JSF & RCD Conference 2006
Dr. Ian Glass from the University of Washington (UW)
in Seattle presented an overview of prenatal diagnosis
and reproductive options for couples who have had a
child with Joubert syndrome (JS). The purpose of
prenatal diagnosis is to provide information to couples
so that they can make informed reproductive decisions
ranging from termination of an affected fetus to
preparation for the birth of an affected child. Couples
who have had a child with JS have a one in four (25%)
chance of having another affected child with each and
every pregnancy. Currently, there is no definitive test
to diagnose JS before birth; however, prenatal
ultrasound and MRI hold the most promise in the short
term. Advances in the genetics of JS may allow for
DNA-based testing in the future. Of note, three genes
associated with JS have been identified. Dr. Glass
summarized the broad variety of reproductive options
available for couples. Based on current experience with
at-risk pregnancies, they proposed initial guidelines
for monitoring at risk pregnancies. Our group's
experience with this approach has been published in the
medical literature (Doherty et al., 2005).
Genetic testing should be strongly
considered, especially if the first affected child has
already tested positive. It is important that the
imaging studies be reviewed by a physician experienced
in the diagnosis of posterior fossa malformations, and
that couples receive genetic counseling. Drs. Glass and
Doherty would be happy to help couples to obtain optimal
information, and they are interested in reviewing
prenatal imaging studies from all pregnancies of couples
who have had an affected fetus or child. The systematic
comparison of prenatal imaging from affected and
unaffected pregnancies will improve understanding of the
early events in JS, and will improve the quality of
prenatal diagnosis in the future. Interested families
should contact Drs. Glass and Doherty through
Dana Knutzen,
UW Joubert Syndrome Center genetic counselor.
| Gestational
age |
Type of
Evaluation |
Details of
evaluation |
| 11-12 wk |
US |
Dates, nuchal
translucency measurement |
| 16 wk |
US |
Full anatomic
survey, close examination of the posterior fossa,
cisterna magna measurement, evaluation for
encephalocele, polydactyly, kidney abnormalities |
| 18 wk |
US |
Vermis
measurements (height, diameter), reexamination
of posterior fossa, cisterna magna measurement,
reevaluation for encephalocele, polydactyly,
kidney abnormalities |
| 20 wk |
US |
Vermis
measurements (height, diameter), reexamination
of posterior fossa, cisterna magna measurement,
reevaluation for encephalocele, polydactyly,
kidney abnormalities |
| 20-22 wk |
MRI |
Evaluation for
supratentorial abnormalities and confirmation of
posterior fossa findings from US |
The slides from the prenatal
diagnosis talk can be viewed at:
http://depts.washington.edu/joubert/prenatald.html
Dr. I Glass and
Dr. D Doherty
Back to Physician
Research Page |
|
|
Printer
friendly version |
| |
|
The views expressed do
not necessarily reflect those of the donors. The articles,
announcements, and resources included on this website are
for information only and should not be considered as medical
advice. Please always consult your physician for medical
advice. The Joubert Syndrome Foundation & Related Cerebellar
Disorders does not endorse any product, service, or theory
referred to on the website.
|