Sick Kids researchers identify gene for Shwachman-Diamond syndrome

December 22, 2002

Researchers at The Hospital for Sick Children (HSC) and the University of Toronto (U of T) have identified the gene that is altered in Shwachman-Diamond syndrome. The researchers studied 250 Shwachman-Diamond syndrome families from around the world and identified two major disease-causing mutations in a gene on chromosome 7. This research is reported in the January issue of the scientific journal Nature Genetics.

Shwachman-Diamond syndrome (SDS) is a relatively rare genetic disorder that occurs in approximately one in 50,000 births. SDS affects many organs in the body. Primary features of SDS include a defect in the pancreas that leads to difficulties in digesting food, hematologic (blood) problems with inadequate production of some types of white blood cells, skeletal abnormalities, and short stature. The hematologic problems make people with SDS prone to severe, sometimes fatal infections, and some die from blood complications such as leukemia or bone marrow failure.

"The identification of the gene is important because it will allow for accurate diagnosis and screening of Shwachman-Diamond syndrome. It will also help us to determine what goes wrong at the molecular level, and this will open the door to the development of new therapies," said Dr. Johanna Rommens, the study's principal investigator, an HSC senior scientist and associate professor of Molecular and Medical Genetics at U of T.

"This discovery will aid in the clinical management of Shwachman-Diamond syndrome," said Dr. Peter Durie, co-principal investigator of the study, an HSC gastroenterologist and senior scientist, and a professor of Paediatrics at U of T. "It is also very important to the families affected by this disease. We have received patient samples from around the world, and the Shwachman-Diamond parent groups from many countries supported this research financially."

Shwachman-Diamond syndrome is an autosomal recessive disease, meaning that a child needs to inherit two mutated genes (one from each parent) in order to have the disease. The SDS gene resides in a region of the human genome that was very difficult to map because it contains a lot of highly repetitious DNA sequence. It was found that in the normal state, every chromosome 7 has two copies of the SDS gene - a functional gene and a non-functional gene relic, called a 'pseudogene'.

"We have determined that the type of genetic mutation that causes Shwachman-Diamond syndrome is gene conversion, in that a piece of the non-functional pseudogene has been introduced into the good copy of the gene, thus disrupting its function. These types of mutations have been seen in more than 90 per cent of SDS patients," said Graeme Boocock, the study's lead author and a University of Toronto graduate student. Boocock is a recipient of a Canadian Institutes of Health Research doctoral research award.
-end-
Other members of the research team are Jodi Morrison, Maja Popovic, Nicole Richards, and Lynda Ellis, all from The Hospital for Sick Children.

This research was supported by the Canadian Institutes of Health Research, Shwachman-Diamond Syndrome Canada, Shwachman-Diamond Syndrome International, Shwachman-Diamond Support of Great Britain, The Harrison Wright Appeal, Shwachman-Diamond Syndrome Support of Australia, Paediatric Consultants Inc., Canadian Genetic Diseases Network of Centres of Excellence, and The Hospital for Sick Children Foundation.

The Hospital for Sick Children, affiliated with the University of Toronto, is Canada's most research-intensive hospital and the largest centre dedicated to improving children's health in the country. Its mission is to provide the best in family-centred, compassionate care, to lead in scientific and clinical advancement, and to prepare the next generation of leaders in child health. For more information, please visit www.sickkids.ca.

Further information for families affected by Shwachman-Diamond syndrome is available on the HSC Web site at http://www.sickkids.ca/mediaroom/custom/SDSgeneQA.asp.

For more information, please contact:
Laura Greer, Public Affairs (away December 24-January 6)
The Hospital for Sick Children
(416) 813-5046
laura.greer@sickkids.ca

Lisa Lipkin, Public Affairs
The Hospital for Sick Children
(416) 813-6380
lisa.lipkin@sickkids.ca

University of Toronto

Related Human Genome Articles from Brightsurf:

240 mammals help us understand the human genome
A large international consortium led by scientists at Uppsala University and the Broad Institute of MIT and Harvard has sequenced the genome of 130 mammals and analysed the data together with 110 existing genomes to allow scientist to identify which are the important positions in the DNA.

The National Human Genome Research Institute publishes new vision for human genomics
The National Human Genome Research Institute this week published its 'Strategic vision for improving human health at The Forefront of Genomics' in the journal Nature.

Interpreting the human genome's instruction manual
Berkeley Lab bioscientists are part of a nationwide research project, called ENCODE, that has generated a detailed atlas of the molecular elements that regulate our genes.

3-D shape of human genome essential for robust inflammatory response
The three-dimensional structure of the human genome is essential for providing a rapid and robust inflammatory response but is surprisingly not vital for reprogramming one cell type into another.

The genome of chimpanzees and gorillas could help to better understand human tumors
A new study by researchers from the Institute of Evolutionary Biology (IBE), a joint center of UPF and the Spanish National Research Council (CSIC), shows that, surprisingly, the distribution of mutations in human tumors is more similar to that of chimpanzees and gorillas than that of humans.

It's in our genome: Uncovering clues to longevity from human genetics
Researchers from Osaka University found that high blood pressure and obesity are the strongest factors reducing lifespan based on genetic and clinical information of 700,000 patients in the UK, Finland and Japan.

New limits to functional portion of human genome reported
An evolutionary biologist at the University of Houston has published new calculations that indicate no more than 25 percent of the human genome is functional.

Synthesizing the human genome from scratch
For the past 15 years, synthetic biologists have been figuring out how to synthesize an organism's complete set of DNA, including all of its genes.

Science and legal experts debate future uses and impact of human genome editing in Gender & the Genome
Precise, economical genome editing tools such as CRISPR have made it possible to make targeted changes in genes, which could be applied to human embryos to correct mutations, prevent disease, or alter traits.

Evolution purged many Neanderthal genes from human genome
Neanderthal genetic material is found in only small amounts in the genomes of modern humans because, after interbreeding, natural selection removed large numbers of weakly deleterious Neanderthal gene variants, according to a study by Ivan Juric and colleagues at the University of California, Davis, published Nov.

Read More: Human Genome News and Human Genome Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.