Article: MRI Findings of the Pancreas in patients with SDS and mutations in the SBDS gene

Magnetic resonance imaging findings of the pancreas in patients with Shwachman-Diamond syndrome and mutations in the SBDS gene.
Medical Imaging Center, Helsinki University Hospital, Helsinki, Finland.
Pancreatic MRI was evaluated in 14 patients with a clinical diagnosis of Shwachman-Diamond syndrome, and the findings were correlated with Shwachman-Bodian-Diamond gene (SBDS) genotype. The findings suggest that patients with mutations in the SBDS gene have a characteristic magnetic resonance imaging pattern of fat-replaced pancreas and that SBDS mutations are unlikely in patients without this pattern.

This article contains charts on how each of the 14 patients pancreatic function was assessed. It lists all 14 patients and how each one’s pancreatic function was assessed and then lists the criteria for their SDS diagnosis. It also lists their neutrophil count (range) and height Z-score. In another chart, it lists how long they were on enzymes--- i.e. lists the age at which the person became pancreatic sufficient. One child was 4 years old when she came off of enzymes (i.e. she was on enzymes until age 4) and another one was 5 years old. Two came off of enzymes at 11 years and one at 22 years, one at 29 years, 3 never took enzymes and the rest are on on-going enzyme replacement.

There were 14 patients. 10 males and 4 females. 13 of them were diagnosed at a median age of 18 months….but one was referred to them at age 13 for suspected SDS. One of the patients was diagnosed with type I diabetes at age 15. With all of our diabetes talk recently, I thought that was an interesting note. The article says hat all patients with SBDS mutations showed fatty pancreas on MRI—the patients without the SBDS mutations and proven PI had NORMAL pancreatic MRIs.

SBDS Protein Expression in Peripheral Blood Leukocytes

Many families have participated in this study through CCHMC (Cincinnati Children's Hospital). For contact information, please visit the Shwachman-Diamond America website. From inforamtion given out at CCHMC:

Why is this research being done?

Shwachman-Diamond Syndrome (SDS) is a rare condition which is usually diagnosed in infancy or early childhood. It can affect a wide range of organs but most commonly the digestion and the blood system are involved. Bone abnormalities and poor growth are also often seen in SDS patients. The main hematologic (blood) problem is reduced prduction of some types of white blood cells by teh bone marrow. The pancreas is normally responsible for digesting food, but in SDS it doesn;t make enough digestive enzymes (e.g. trypsin and amylase). However, we have found that people with SDS may have quite different symptoms in teh various organs. In some people, for example, the pancreatic problem is severe and patients need to take extra digestive enzymes with meals. In others, digestive function may improve enough to allow the enzymes to be discontinued. Similarly, some people have more difficulties with their blood problem than others. Some of our research is directed at trying to explain why these differences occur from one individual to another.

Researchers at th Hospital for Sick Children have recently identified the altered gene (SBDS) gene that causes Shwachman-Diamond Syndrome. To date, a number of genetic mutations (mistakes in the SBDS gene) have been found in people who have this syndrome. In addition to the 3 common mutations which account for 75% of all mutations found, there are a ariety of less common mutations.

Healthy people with the normal SBDS gene make SBDS protein in their cells, whereas patients with mutations of teh SBDS gene do not produce this protein or only make very little. This special protein can be measured in blood samples. The amount of the SBDS protein detected in teh blood may vary depending on the tpe of SBDS mutation that is inherited. We think it is important to measure the amount of SBDS protein because it may help us to understand why SDS affects people differently. In addition, we think that measuring the SBDS protein in the blood may be helpful to make a diagnosis of SDS (or rule out the diagnosis), because it is not always possible to screen for all the SBDS mutations.

To do this, we need to test the SBDS protein in a defined group of people, who have common or rare SBDS mutations as well as people who have medical problems that may or may not be due to SBDS mutations. The later group includes children or adults who have a problem in the bone marrow or pancreas and/or skeleton that is suggestive of SDS but no identified mutations in the SDS gene. We will compare the results from people who are healthy as well as people who are known to be carriers such as parents of known SDS patients.

We are collaborating with Drs. Peter Durie and Johanna Rommens at the Hospital for Sick Cildren in Toronto and Dr. Akiko Shimamura at the University of Washington, as well as Drs. Elena Nicolis and MarcoCipolli in Verona, Italy, who will be measuring the corresponding SBDS mRNA in your blood sample. mRNA transmits the information from the gene (DNA) in order to make the protein. Since the SBDS mRNA controls the manufacture of SBDS protein, pople with SBDS mutations may also have very little SBDS mRNA. we will compare the SBDS mutations may alos have very little SBDS mRNA. We will compare the SBDS mRNA content with the SBDS protein level in each patient from our defined groups.

The Common SBDS Mutations

The common SBDS mutations are found on chromosome 7, exon 2—

[183_184TA-->CT] K62X


[258+2T-->C] 84Cfs3


[183_184TA-->CT and 258+2T -->C] K62X