News and Publications

Division of Hematology

Ernest Beutler, M.D., Division Head

The Genetics of Human Diseases

E. Beutler, P. Lee, C. West, T. Gelbart, C. Halloran, J. Sipe, J. Waalen

The main focus of our research program is to gain understanding of the factors that determine clinical expression of genetic diseases. In many places, much effort is being expended in attempting to understand disorders of complex genetic origin, those in which many genes are involved, but it is often not realized that our understanding of single gene disorders is quite incomplete. In monogenic diseases, such as Gaucher disease, hemochromatosis, or sickle cell disease, persons inheriting the same mutations often have markedly different clinical manifestations. Thus, we have shown that some homozygotes for the common 1226G mutation of glucocerebrosidase will have severe Gaucher disease with massively enlarged liver and spleen or with extensive bone lesions whereas others have only very mild disease manifestations.

Our primary focus in the past year has been the iron storage disease hemochromatosis. While it had commonly been believed that up to 95% of persons homozygous for the 845GÆA (C282Y) mutation of the HFE gene ultimately developed hemochromatosis, we found that only 1 in 152 homozygotes, ascertained in a collaborative study with Kaiser Permanente of Southern California, had serious disease that could be attributed to iron storage. Studies done previously had assumed that symptoms such as arthritis, diabetes, or cardiac arrhythmias in homozygotes were due to iron storage, but in the large epidemiologic study that we have performed, it has become apparent that these symptoms are no more common in homozygotes for iron storage disease than in control subjects who have not inherited the mutant HFE genes.

The large population of patients that we have been able to study has also allowed us to test the suggestion that heterozygotes for hemochromatosis mutations have a propensity to develop cardiovascular disease or cancer. Our analysis of the data shows no such effect.

In order to find genes that may modulate the expression of hemochromatosis and account for marked iron storage in some subjects while little or no iron storage occurs in others, we have sequenced most of the proteins known to regulate iron metabolism (Table 1). Polymorphisms in these genes do not account for variation in expression of the HFE mutations. We did, however, identify a mutation in the serum transferrin gene that is clearly a risk factor for iron deficiency.

Our collaborative study with Kaiser Permanente has permitted us to create a very large database of DNA samples from individuals of known age, sex, and ethnic origin. This information has enabled us, for the first time, to determine the gene frequencies of mutations for relatively uncommon diseases, allowing us to predict the birth incidence. Our studies of galactosemia suggest that most infants with galactosemia are detected by screening studies, but that there are fewer pyruvate kinase­ deficient individuals diagnosed than one should expect to find in the population. We have also developed evidence that a missense mutation in the gene for fatty acid amide hydrolase is a risk factor for drug abuse.

We have continued our study of other diseases caused by mutations in single genes.

The study of Gaucher disease, its pathogenesis, and its treatment have been seriously impeded by the lack of an animal model for the disease. Mice homozygous for targeted disruption of the glucocerebrosidase gene do not live past birth. We have now created a mouse model for the disease by harvesting hematopoietic stem cells from the livers of homozygous fetuses and transplanting these cells into irradiated mice. Because macrophages, the storage cells of Gaucher disease, are of hematopoietic stem cell origin, these chimeric mice resemble patients with Gaucher disease. Indeed, our preliminary studies show that glucocerebroside is stored in the spleens and livers of such animals. However they do not show enlargement of the spleen or Gaucher cells in spleen, liver, or bone marrow.

We have also identified mutations in patients with a variety of genetic disorders, including atransferrinemia, glucose-6-dehydrogenase deficiency, pyruvate kinase deficiency, and adenylate kinase deficiency.

PUBLICATIONS

Balicki, D., Beutler, E. Gene therapy of human disease. Medicine (Baltimore) 81:69, 2002.

Balicki, D., Putnam, C.D., Scaria, P.V., Beutler, E. Structure and function correlation in histone H2A peptide-mediated gene transfer. Proc. Natl. Acad. Sci. U. S. A. 99:7467, 2002.

Beutler, E. Biography of Susumu Ohno. In: Biographical Memoirs, Vol. 81. National Academy of Sciences, Washington, DC, 2002, p. 3.

Beutler, E. The Cline affair. Mol. Ther. 4:396, 2001.

Beutler, E. Collection and liquid preservation of red cells. In: Rossi's Principles of Transfusion Medicine, 3rd ed. Stowell, C., et al. (Eds.). Lippincott Williams & Wilkins, Baltimore, in press.

Beutler, E. Discrepancies between genotype and phenotype in hematology: an important frontier. Blood 98:2597, 2001.

Beutler, E. DNA-based diagnosis of red cell enzymopathies: how we threw out the baby with the bathwater [comment]. Blood 97:3325, 2001.

Beutler, E. Erythrocyte enzymopathies. In: Oxford Textbook of Medicine, 4th ed. Warrell, D.A., Cox, T.M., Firth, J.D. (Eds.). Oxford University Press, New York, in press.

Beutler, E. G6PD. In: The Encyclopedia of Molecular Medicine. Creighton, T.E. (Ed.). Wiley & Sons, New York, 2002, p. 1449.

Beutler, E. Glucocerebrosidase. In: The Encyclopedia of Molecular Medicine. Creighton, T.E. (Ed.). Wiley & Sons, New York, 2002, p. 1434.

Beutler, E. Glucose-6-phosphate dehydrogenase deficiency. In: NORD Guide to Rare Diseases. Lippincott Williams & Wilkins, New York, in press.

Beutler, E. Hemochromatosis. In: Encyclopedia of the Human Genome. Cooper, D.N. (Ed.). Nature Publishing Group, New York, in press.

Beutler, E. Hemoglobin. In: Encyclopedia of Public Health. Breslow, L. (Ed.). Macmillian, New York, in press.

Beutler, E. Hemoglobinopathies. In: Encyclopedia of Public Health. Breslow, L. (Ed.). Macmillian, New York, in press.

Beutler, E. The molecular basis of paroxysmal nocturnal hemoglobinuria. J. Clin. Ligand Assay 24:210, 2001.

Beutler, E. Pyruvate kinase deficiency. In: NORD Guide to Rare Diseases. Lippincott Williams & Wilkins, New York, in press.

Beutler, E. Red cell metabolism. In: Rossi's Principles of Transfusion Medicine, 3rd ed. Stowell, C., et al. (Eds.). Lippincott Williams & Wilkins, Baltimore, in press.

Beutler, E. Sickle cell disease. In: Encyclopedia of Public Health. Breslow, L. (Ed.). Macmillian, New York, in press.

Beutler, E. Subunit structure of the hexosaminidase isozymes. Adv. Genet. 44:93, 2001.

Beutler, E., Felitti, V.J. The C282Y mutation does not shorten life span. Arch. Intern. Med. 162:1196, 2002.

Beutler, E., Felitti, V., Ho, N., Gelbart, T. Relationship of body iron stores to levels of serum ferritin, serum iron, unsaturated iron binding capacity and transferrin saturation in patients with iron storage disease. Acta Haematol. 107:145, 2002.Gombart

Beutler, E., Felitti, V.J., Koziol, J.A., Gelbart, T. Penetrance of the 845G*A (C282Y) HFE hereditary haemochromatosis mutation in the USA: reply. Lancet, in press.

Beutler, E., Felitti, V.J., Koziol, J.A., Ho, N.J., Gelbart, T. Penetrance of the 845G*A (C282Y) HFE hereditary haemochromatosis mutation in the USA. Lancet 359:211, 2002.

Beutler, E., Gelbart, T., Miller, W. Severe jaundice in a patient with a previously undescribed glucose-6-phosphate dehydrogenase (G6PD) mutation and Gilbert syndrome. Blood Cells Mol. Dis. 28:104, 2002.

Beutler, E., Gelbart, T., West, C. Synergy between TLR2 and TLR4: a safety mechanism. Blood Cells Mol. Dis. 27:728, 2001.

Beutler, E., Griffin, M.J., Gelbart, T., West, C. A previously undescribed nonsense mutation of the HFE gene. Clin. Genet. 61:40, 2002.

Beutler, E., Mason, J. Allogeneic stem cell transplantation. In: Allogeneic Stem Cell Transplantation: Clinical Research and Practice. Laughlin, M.J., Lazarus, H.M. (Eds.). Humana Press, Totowa, NJ, in press.

Beutler, E., Vulliamy, T. Hematologically important mutations: glucose-6-phosphate dehydrogenase. Blood Cells Mol. Dis. 28:93, 2002.

Beutler, E., West, C. Polymorphisms in the 5´ flanking region of the HFE gene: linkage disequilibrium and relationship to iron homeostasis. Blood Cells Mol. Dis. 28:191, 2002.

Colwell, C.W., Jr., Beutler, E., West, C., Hardwick, M.E., Morris, B.A. Erythrocyte viability in blood salvaged during total joint arthroplasty with cement. J. Bone Joint Surg. [Am.] 84-A:23, 2002.

Herschel, M., Beutler, E. Low glucose-6-phosphate dehydrogenase enzyme activity level at the time of hemolysis in a male neonate with the African type of deficiency. Blood Cells Mol. Dis. 27:918, 2001.

Kaplan, M., Hammerman, C., Beutler, E. Heterozygosity for a polymorphism in the promoter region of the UGT1A1 gene. J. Hepatol. 35:148, 2001.

Kaplan, M., Hammerman, C., Vreman, H.J., Stevenson, D.K., Beutler, E. Acute hemolysis and severe neonatal hyperbilirubinemia in glucose-6-phosphate dehydrogenase-deficient heterozygotes. J. Pediatr. 139:137, 2001.

Koziol, J.A., Ho, N.J., Felitti, V.J., Beutler, E. Reference centiles for serum ferritin and percentage of transferrin saturation, with application to mutations of the HFE gene. Clin. Chem. 47:1804, 2001.

Lee, P.L., Gelbart, T., West, C., Halloran, C., Felitti, V., Beutler, E. A study of genes that may modulate the expression of hereditary hemochromatosis: transferrin receptor-1, ferroportin, ceruloplasmin, ferritin light and heavy chains, iron regulatory proteins (IRP)-1 and -2, and hepcidin. Blood Cells Mol. Dis. 27:783, 2001.

Lee, P.L., Gelbart, T., West, C., Halloran, C., Sipe, J.C., Beutler, E. Mutations in iron-regulatory protein 2 (IRP2) and lack of association with sporadic Parkinson's disease. Mov. Disord., in press.

Lee, P.L., Halloran, C., Trevino, R., Felitti, V., Beutler, E. Human transferrin G277S mutation: a risk factor for iron deficiency anaemia. Br. J. Haematol. 115:329, 2001.

Peters, L.L., Lane, P.W., Andersen, S.G., Gwynn, B., Barker, J.E., Beutler, E. Downeast anemia (dea), a new mouse model of severe nonspherocytic hemolytic anemia caused by hexokinase (HKI) deficiency. Blood Cells Mol. Dis. 27:850, 2001.

Sipe, J.C., Chiang, K., Gerber, A.L., Beutler, E., Cravatt, B.F. A missense mutation in human fatty acid amide hydrolase associated with problem drug use. Proc. Natl. Acad. Sci. U. S. A. 99:8394, 2002.

Sipe, J.C., Lee, P., Beutler, E. Brain iron metabolism genes and neurodegenerative disorders. Dev. Neurosci., in press.

Suzuki, M., West, C., Beutler, E. Large-scale molecular screening for galactosemia alleles in a pan-ethnic population. Hum. Genet. 109:210, 2001.

Suzuki, M., Zheng, H.-Y., Takasaka, T., Sugimoto, C., Kitamura, T., Beutler, E., Yogo, Y. Asian genotypes of JC virus in Japanese-Americans suggests familial transmission. J. Virol., in press.

Waalen, J., Felitti, V.J., Beutler, E. Metastatic carcinomatous cirrhosis and hepatic hemosiderosis. Arch. Pathol. Lab. Med. 126:128, 2002.

Waalen, J., Felitti, V.J., Beutler, E. Reference limits of blood hemoglobin concentrations in men and women differ even when iron deficiency is eliminated. Br. J. Med., in press.

Waalen, J., Felitti, V., Gelbart, T., Ho, N.J., Beutler, E. Prevalence of hemochromatosis-related symptoms among individuals with mutations of the HFE gene. Mayo Clin. Proc. 77:522, 2002.