Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UCSD researchers identify chromosome location for 2nd form of Joubert syndrome

04.09.2003


Physicians may be a step closer to pre-natal diagnosis of a rare genetic disorder called Joubert syndrome. This condition, present before birth, affects an area of the brain controlling balance and coordination.



New findings from the University of California, San Diego (UCSD) School of Medicine have identified chromosome 11 as a second site for a gene or genes that cause Joubert syndrome, a disorder that affects about 1 in 30,000 individuals. Prior to this study, chromosome 9 had been the only known site with gene mutations causing the disorder.

The new study, published online in the September issue of the American Journal of Human Genetics, focused on three Middle Eastern families whose relatives had inter-married and passed the genetic defect to several family members.


Characterized by absence or underdevelopment of a brain region called the cerebellar vermis, and by a malformed brain stem, Joubert syndrome affects individuals to varying degrees across the spectrum of motor and mental development. Its most common features include lack of muscle control and decreased muscle tone; an abnormal breathing pattern called hypernea, in which babies pant; abnormal eye and tongue movements; and mild or moderate retardation. The type of Joubert syndrome now traced to chromosome 11 also includes eye or kidney problems, in addition to the classical symptoms associated with the disorder.

“The hunt for genes for this syndrome has been extremely slow and none are currently known, due to the rarity of the syndrome,” said the study’s senior author, Joseph Gleeson, M.D., UCSD assistant professor of neurosciences. “The main problem in identifying genes has been the small number of patients appropriate for genetic analysis.”

This led Gleeson’s team to an intensive patient recruiting effort and a change in the way the analysis was being performed.

Joubert syndrome is inherited in an autosomal recessive manner, which means that both parents carry the mutant version of the gene, while showing no signs of the disease themselves. To increase their subject pool for research, the Gleeson team focused on the Middle East, where families are larger and inter-marriage between cousins is an accepted custom. Working with collaborators in Oman, the United Arab Emirates, Saudi Arabia, Jordan and Pakistan, the UCSD researchers obtained DNA samples from affected and unaffected individuals in 20 families.

Using sophisticated genetic screening tools, the researchers identified a common genetic region in seven children from three affected families who displayed the form of Joubert syndrome with eye and kidney problems. These patients included a northern Pakistani child of first cousins, who displayed visual impairment and kidney cysts in addition to the characteristic breathing abnormality and muscle coordination problem. Two of six children of first cousins from the United Arab Emirates, exhibited Joubert features such as brain malformations (as revealed on an MRI scan), impaired vision, jerky eye movements and a malformed retina. Three children from another United Arab Emirates family experienced panting respirations, balance problems, retinal dystrophy and moderate visual impairment.

The study’s authors noted that the variability of symptoms in the affected individuals suggests that there may be genetic modifiers that influence the disease severity and expression of symptoms.

Gleeson, who has studied Joubert syndrome for several years, noted “parents of affected children are just craving for information, to understand the basis for this disorder and something about the prognosis. The most heart wrenching thing is parents who are reluctant to get pregnant again because they have had a single child with this condition.”

He added that the possibility of developing a genetic screening test gives his group an additional incentive to discover the gene as soon as possible.

“We don’t yet know the exact genes involved; this is an incremental step,” Gleeson said. “But, we’re getting closer to providing the information these parents so desperately want.”

In addition to Gleeson, additional researchers include first-author Lesley C. Keeler, M.S., Sarah E. Marsh, M.S., Esther P. Leeflang, Ph.D., Neurogenetics Laboratory, UCSD Division of Pediatric Neurology; Christopher G. Woods, M.D., Molecular Medicine Unit and Yorkshire Clinical Genetics Service, St. James’ University Hospital, Leeds, United Kingdom; and Aithala Gururaj, Lihadh Al-Gazali, DCH, Laszlo Sctriha, M.D., Ph.D., Department of Pediatrics, United Emirates University, Al Ain, UAE.

The study was performed collaboratively with the Marshfield Center for Genetics in Wisconsin and funded by the March of Dimes.

Sue Pondrom | UCSD
Further information:
http://health.ucsd.edu/news/2003/09_03_Gleeson.html
http://gleesongenetics.ucsd.edu/
http://www.joubertsyndrome.org/index.htm

More articles from Health and Medicine:

nachricht Hot cars can hit deadly temperatures in as little as one hour
24.05.2018 | Arizona State University

nachricht 3D images of cancer cells in the body: Medical physicists from Halle present new method
16.05.2018 | Martin-Luther-Universität Halle-Wittenberg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>