This study will examine blood for factors that may cause or prevent diseases involving red blood cells. Red blood cells carry oxygen to body tissues. A better understanding of these cells may help lead to better treatment of diseases involving red blood cells.

Patients of all ages with red cell abnormalities in the following categories may be eligible for this study:

-Known red blood cell diseases, such as hemoglobinopathies

-Red blood cell diseases of unknown cause, such as hemolysis of unknown cause

-Red blood cell abnormalities with no overt clinical disease, such as hereditary persistence of fetal hemoglobin

Participants undergo the following procedures:

-Medical history

-Physical examination

-Standard medical tests related to the individual's red blood cell condition

-Blood draw for the following purposes:

a) Testing for syphilis and for the hepatitis B and C, HIV, and HTLV-1viruses, and for a pregnancy test for women who can become pregnant

b) Research purposes. This blood is analyzed for genes, proteins, sugars, and fat molecules.

Further Study Details: 

Expected Total Enrollment:  9999999

Studies of erythroid cells, both normal and mutant, have provided fundamental insights into structure-function relationships of proteins, and the molecular basis of diseases involving those cells. The discovery of sickle hemoglobin as having an abnormal electrophoretic mobility marked the beginning of the molecular medicine era. The advent of recombinant DNA technology and sequencing methodologies resulted in the characterization of erythroid cells well beyond that of protein-based studies to include gene structure and expression. Globin gene research, in particular, has provided a wealth of information about the expression, regulation and insulation of mammalian genes. Studies of red cell enzymes provided the means to prevent enzymopathy-based hemolysis. Safe transfusion of red cells has been made possible by the characterization of blood group carrier molecules on those cells. Related studies of those membrane molecules have greatly enhanced the understanding of malarial pathogenesis. Hence, there is strong evidence that fundamental clinical advances in the field of erythroid biology have been based upon the careful description of informative erythroid phenotypes. Clinically based correlation of genotype and phenotype is a proven, systematic approach for understanding the molecular basis of disease.

With the completion of the sequencing of the human genome, a more complete, genetically based description of erythroid cells is now achievable. Efforts aimed toward haplotype mapping will further enhance genotype-phenotype correlation directly from clinical samples. Considerable progress has already been made in this regard using "normal" human erythroid cells. In contrast to classic studies involving single genes or proteins, computational biology and high-throughput technologies permit the analysis of complex erythroid phenotypes. This information will be invaluable for understanding those molecular mechanisms that are altered in disease states involving erythroid cells.

The immediate aim of this protocol is to perform genotype-phenotypic analyses in humans with informative erythroid phenotypes. These studies are expected to result in detailed clinical phenotyping and the collection and banking of clinical specimens for further study. In addition, we predict an ongoing growth of new technologies that may eventually be used for molecular and genetic phenotyping of clinical samples (examples include oligonucleotide chips and high-throughput mass spectroscopy). Based upon this prediction, we plan to use the samples collected here to assess possible clinical uses of those technologies as they become available. The eventual aim is the discovery of identifiers that may be predictive of disease pathogenesis, severity or clinical response to intervention.

Genders Eligible for Study:  Both

Accepts Healthy Volunteers

Criteria

INCLUSION CRITERIA:
A clinically definable erythroid phenotype as defined by:
Group 1: Patients with known erythroid diseases (example: hemoglobinopathies).
OR
Group 2: Patients with erythroid diseases of unknown etiology (example: hemolysis of unknown etiology).
OR
Group 3: Patients with an informative erythroid phenotype in the absence of overt clinical disease (example: hereditary persistence of fetal hemoglobin).
For adults: Ability to comprehend the investigational nature of the study and provide informed consent.
For minors: Written informed consent from one parent or guardian. Informed assent from minors: The process will be explained to the minor on a level of complexity appropriate for their age and ability to comprehend.
Women who are pregnant or breastfeeding are eligible to enroll in this protocol.
Age range: Birth to greater than 80+ years. Unlimited
EXCLUSION CRITERIA:
Subjects who are unable to comprehend the investigational nature of the laboratory research are ineligible to enroll in this protocol.

Maryland
      National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), 9000 Rockville Pike,  Bethesda,  Maryland,  20892,  United States; Recruiting

Study ID Numbers:  050085; 05-DK-0085
Record last reviewed:  January 13, 2005
Last Updated:  March 5, 2005
Record first received:  January 25, 2005
ClinicalTrials.gov Identifier:  NCT00102245
Health Authority: United States: Federal Government
ClinicalTrials.gov processed this record on 2005-04-08