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The Role of Susceptibility to Thrombosis in the Pseudotumor Cerebri of Nephropathic Cystinosis: A Case-Control Study

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00071903
Recruitment Status : Completed
First Posted : November 4, 2003
Last Update Posted : July 2, 2017
Information provided by:
National Institutes of Health Clinical Center (CC)

Brief Summary:

This study will examine whether the tendency to have thrombosis, or the formation of blood clots inside blood vessels, has a role in the development of pseudotumor cerebri (PTC). PTC causes symptoms and signs of isolated elevated blood pressure in the cranium, or covering of the brain. The disorder can lead to significant, negative effects on the visual system. Increased pressure of the cerebrospinal fluid, that is, fluid around the brain, is a factor, but the cause of the disorder is not clear. There has been documentation of clustering of PTC within families. It suggests that potential genetic polymorphisms-abilities to take on different forms-may become evident after exposure to conditions known to trigger PTC.

Thrombosis comes about by interactions between genetic and environmental or acquired factors, or both, resulting in a blood clot at a specific time and location. Because the disease occurs in episodes, the interaction of the genetic and nongenetic risk factors is important. Cystinosis is a recessive disorder caused by deposits of cystine within the lysosomes of cells-that is, sac-like cell parts that contain various enzymes. Involvement of the kidneys remains the primary characteristic, eventually leading to renal failure. Of all of the risk factors that make it easier for blood clotting, a high level of a substance called homocysteine is of particular interest. Too much homocysteine in blood plasma is a common finding in patients with kidney failure, and it has been recently identified as an independent risk factor for diseases of the blood vessels.

Participants of all ages who meet the Dandy criteria for PTC may be eligible for this study. Pregnant women will be excluded. There will also be a control group of nephropathic cystinosis patients who do not have PTC.

Participants will be asked to undergo the following tests and procedures:

  • Medical history.
  • Physical examination, to evaluate the eye and nervous systems.
  • Collection of blood for DNA and other tests.
  • Collection of cerebrospinal fluid, through a procedure called lumbar puncture or spinal tap.

The evaluation of patients will generally last 3 to 4 days. For the collection of cerebrospinal fluid, the patient's skin on the back will be numbed with a local anesthetic. A special needle will be inserted into the back, and a small amount of the fluid will be drawn through the needle. There will be pain for a minute, although there can be a headache lasting 24 hours. Also, there may be bruising, local pain, bleeding, or infection where the needle enters. Patients may also have a magnetic resonance imaging scan of their head. During the MRI scan, patients will lie still on a table that slides in and out of a metal cylinder surrounded by a strong magnetic field. Patients will be able to communicate with the MRI staff at all times and may ask to be moved out of the machine at any time.

Condition or disease
Pseudotumor Cerebri Cystinosis

Detailed Description:

During the follow-up of cystinosis patients under protocol #78-HG-0093 "Use of Cysteamine in the Treatment of Cystinosis", we found that 6 of our NIH patients developed papilledema and were diagnosed with pseudotumor cerebri (PTC), whose occurrence has not been previously reported in cystinosis. The goal of this protocol is to identify the role of thrombosis susceptibility in the development of PTC in nephropathic cystinosis patients in view of our recent findings regarding genetic susceptibility to thrombosis in PTC in general. We propose a case-control study. A total of 9 nephropathic cystinosis patients who developed PTC and 9 control nephropathic cystinosis patients without PTC will be screened based upon a thrombosis susceptibility screening panel, including total homocysteine, protein C and S, antithrombin III, fibrinogen, Factor VIII, Factor IX, Factor XI levels, testing for PT, PTT, activated protein C resistance, antiphospholipid antibodies (ACA panel and Lupus AC) and screening for FV Leiden mutation, FV G1628A polymorphism, FV R2 allele, Prothrombin 20210 mutation and 5,10-methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism in patients with severe homocysteinemia (greater than or equal to 100 micro mol/l).

We will compare the prevalence of the factors that lead to thrombosis susceptibility in the cases and controls.

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Study Type : Observational
Enrollment : 18 participants
Official Title: The Role of Susceptibility to Thrombosis in the Pseudotumor Cerebri of Nephropathic Cystinosis: A Case-Control Study
Study Start Date : October 30, 2003
Study Completion Date : July 18, 2008

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   2 Years to 50 Years   (Child, Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

The inclusion criteria include only a confirmed diagnosis of pseudotumor cerebri (past or present) in a patient with nephropathic cystinosis. Patients will be diagnosed as having pseudotumor cerebri based upon modified Dandy criteria:

  1. signs and symptoms related to increased intracranial pressure;
  2. no localizing neurological signs with the exception of unilateral or bilateral sixth nerve palsy;
  3. neuroimaging study showing no mass lesion or hydrocephalus;
  4. elevated opening pressure with normal cerebrospinal fluid contents on lumbar puncture.

Nephropathic cystinosis patients of all ages who meet the Dandy criteria for PTC will be considered for the study.


Pregnant patients will be excluded from the study.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00071903

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United States, Maryland
National Institutes of Health Clinical Center, 9000 Rockville Pike
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
Layout table for additonal information Identifier: NCT00071903    
Other Study ID Numbers: 040010
First Posted: November 4, 2003    Key Record Dates
Last Update Posted: July 2, 2017
Last Verified: July 18, 2008
Keywords provided by National Institutes of Health Clinical Center (CC):
Idiopathic Intracranial Hypertension
Kidney Involvement
Lysosomal Storage Disorder
Pseudotumor Cerebri
Susceptibility to Thrombosis
Nephropathic Cystinosis
Intracranial Hypertension
Additional relevant MeSH terms:
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Pseudotumor Cerebri
Fanconi Syndrome
Disease Susceptibility
Embolism and Thrombosis
Vascular Diseases
Cardiovascular Diseases
Disease Attributes
Pathologic Processes
Lysosomal Storage Diseases
Metabolism, Inborn Errors
Genetic Diseases, Inborn
Metabolic Diseases
Renal Tubular Transport, Inborn Errors
Kidney Diseases
Urologic Diseases
Intracranial Hypertension
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases