Pediatric Wiskott-Aldrich Syndrome
- Author: Robert A Schwartz, MD, MPH; Chief Editor: Harumi Jyonouchi, MD more...
Background
Wiskott-Aldrich syndrome (WAS) was first described by Wiskott in 1937 and was further characterized by Aldrich in 1954. It is an X-linked recessive immunodeficiency disorder characterized by the triad of recurrent bacterial sinopulmonary infections, eczema (atopiclike dermatitis), and a bleeding diathesis caused by thrombocytopenia and platelet dysfunction. However, only a third of patients with the syndrome have the classic triad.[1] Almost 90% of patients have manifestations of thrombocytopenia at presentation, 20% have only hematologic abnormalities, 5% have only infectious manifestations, and none have only eczema.[2] Other symptoms may include autoimmune phenomena and malignancies.[3]
An infant with WAS is seen in the image below.
This 10-month-old infant presented with bloody diarrhea at age 4 months followed by recurrent otitis media infections. A maternal uncle had Wiskott-Aldrich Syndrome (WAS). Note the mild malar eczema and pretibial ecchymoses in this nonambulatory child. His diagnosis was confirmed by immunologic parameters, thrombocytopenia, and low platelet volume. Wiskott-Aldrich syndrome occurs in males but can occur in females when the X chromosome that contains the functional allele is inactivated, although this is rare. There may be multiple revertant genotypes in patients with Wiskott-Aldrich syndrome.[4]
The gene for the Wiskott-Aldrich syndrome protein (WASp) is localized to Xp11.22-23 and consists of 12 exons that encode a 502 amino acid (53 kD) protein. WASp is a cytosolic protein expressed on all hematopoietic cell lineages and is essential for normal antibody function, T-cell responses, and platelet production.[5] It also regulates actin polymerization, transcription, and a selective, post-transcriptional role in Th2 effector function.[6] About 300 mutations have been found throughout the gene and can include base pair substitutions, insertions, and deletions. These mutations can result in different clinical phenotypes, including classic Wiskott-Aldrich syndrome, X-linked thrombocytopenia, intermittent thrombocytopenia, and neutropenia.[7, 8]
The type of specific mutation, its location within the gene, and its effect on protein expression appear to determine an individual patient's clinical phenotype.[9]
Pathophysiology
WASP is a key regulator of actin polymerization in hematopoietic cells. As a cytoskeletal regulator, it is necessary for induction of normal immunity. WASp functions as a bridge between signaling and movement of the actin filaments in the cytoskeleton. WASp has several well-defined domains (pleckstrin, cofilin, verprolin, SH3) that are involved in signaling, cell locomotion, and immune synapse formation.
In vitro studies with T cells, platelets, phagocytes, and dendritic cells of patients with Wiskott-Aldrich syndrome reveal defects in the formation of microvilli, filopodia, phagocytic vacuoles, and podosomes, respectively; these structures depend on cytoskeletal reorganization of actin filaments. Researchers also identified many different mutations that interfere with the protein binding to Cdc42 and Rac GTPases, among other binding partners, most of which are involved in regulation of the actin cytoskeleton of lymphocytes.[10, 11] The actin cytoskeleton is responsible for cellular functions, such as growth, endocytosis, exocytosis, and cytokinesis.
Mutations of WASP are located throughout the gene and either inhibit or dysregulate normal WASp function. WASp facilitates the nuclear translocation of nuclear factor kappa-B (NF-kB) and was shown to play an important role in lymphoid development and in the maturation and function of myeloid monocytic cells. In mice, WASp was found to be essential for NF-ATp activation, and for nuclear translocation of p-Erk, Elk1 phosphorylation, and c-fos gene expression in T cells. These defects in mutated forms of WASP are the likely etiology of defective IL-2 expression and T-cell proliferation in Wiskott-Aldrich syndrome.
Clot formation is interrupted by impaired formation of fibrin strands. WASp binds to calcium and integrin binding protein (CIB) on platelets. The complex of CIB and mutated WASp reduces alpha2-beta3 integrin mediated cell adhesion and causes defective platelet aggregation, resulting in bleeding.
Research has shown phenotype-genotype correlation. Classic Wiskott-Aldrich syndrome, X-linked thrombocytopenia, and X-linked neutropenia occurs when WASp is absent, when mutated WASp is expressed, and when missense mutations occur in the Cdc42-binding site, respectively. Although exceptions are noted and although predicting long-term prognosis based on these findings is difficult, this research may lead the way to curative hematopoietic stem cell transplantation and gene therapy.[7] Further research is underway to identify WASp-associated proteins, such as WASp-interacting protein (WIP) and several Wiskott-Aldrich syndrome proteins verprolin homologous (WAVE).[12, 13, 14, 15]
Epidemiology
Frequency
United States
The estimated incidence of Wiskott-Aldrich syndrome in the United States is 1 in 250,000 live male births.[16]
International
The frequency in the European population has been reported to be similar to that of the United States (1 in 250,000 live male births). A study from Switzerland reported the incidence of Wiskott-Aldrich syndrome is 4.1 cases per 1 million live births. The same study also examined the prevalence of Wiskott-Aldrich syndrome in several national registries (ie, Italy, Japan, Switzerland, Sweden) and found that this condition occurred in 2-8.8% of patients with primary immunodeficiencies.[17] A similar range has been documented in a national registry in Ireland, as well.[18]
Mortality/Morbidity
Morbidity and mortality have gradually improved with better antibiotics, advances in blood banking, better supportive care, and the ability to successfully provide immune reconstitution by stem cell transplantation. Median survival has increased from 8 months in patients born before 1935 to longer than 6 years in patients born after 1964.[16] In one case series, 94 surviving patients ranged in age from 1-35 years, with a median of 11 years; the average age of patients who died was 8 years.[2]
In one study the reported cause of death among patients who did not receive bone marrow transplants were infection (44%), bleeding (23%), or malignancy (26%).[2] Younger patients are more likely to die from bleeding, children are more likely to die from infection, and children and young adults die most often from malignancies. Malignancies may occur in children but are more frequent in affected adults. Lymphomas occur in 26% of patients aged 20 years and older. In one series, 12% of patients developed malignancies, primarily lymphoreticular tumors, and leukemia. In that series, the relative risk of malignancy was more than 100-fold that of normal and the risk increased with age.[16]
The average lifespan for patients who do not receive immune reconstitution is the second to third decade of life, although patients have survived into the fifth decade of life. Following major histocompatibility complex (MHC)–matched stem cell transplantation, the patient who escapes graft versus host disease (GVHD) usually has completely normal immune function and, therefore, has an excellent prognosis for normal survival.[19] Survival rates after stem cell transplant have continued to improve, particularly after more recent emphasis on performing these procedures as soon as possible after diagnosis.[20]
Race
Wiskott-Aldrich syndrome has been reported in individuals of European, African, and Asian ancestry; however, Blacks and Asians are less likely to be affected. One large series of 301 cases of Wiskott-Aldrich syndrome from 149 families reported that 8 families were black and 4 families were Chicano.[16] Of the 40 families whose ancestry was traced outside North America, 38 emigrated from Europe.
Sex
More than 90% of affected patients are male, but females have been reported in the literature. Females typically have no family history. In some cases, females have been shown to have nonrandom inactivation of the X chromosome bearing the functional Wiskott-Aldrich syndrome allele.[21]
Age
Age at presentation ranges from birth to 25 years. In one review, the average age of presentation was 21 months.[2, 16] Male infants present at birth with petechiae and ecchymoses. Infections usually begin in early infancy after maternal immunoglobulin G (IgG) is lost during the first 3 months of life. The frequency of infections usually increase with age. Patients are especially susceptible to encapsulated organisms. Eczema develops during the first year of life and resembles classic atopic dermatitis. Malignancies may occur in children but are more frequent in affected adults. Lymphomas occur in 26% of patients aged 20 years and older.
Blundell MP, Bouma G, Calle Y, Jones GE, Kinnon C, Thrasher AJ. Improvement of migratory defects in a murine model of Wiskott-Aldrich syndrome gene therapy. Mol Ther. May 2008;16(5):836-44. [Medline].
Sullivan KE, Mullen CA, Blaese RM, Winkelstein JA. A multiinstitutional survey of the Wiskott-Aldrich syndrome. J Pediatr. Dec 1994;125(6 Pt 1):876-85. [Medline].
Conley ME, Notarangelo LD, Etzioni A. Diagnostic criteria for primary immunodeficiencies. Representing PAGID (Pan-American Group for Immunodeficiency) and ESID (European Society for Immunodeficiencies). Clin Immunol. Dec 1999;93(3):190-7. [Medline].
Davis BR, Yan Q, Bui JH, Felix K, Moratto D, Muul LM, et al. Somatic mosaicism in the Wiskott-Aldrich syndrome: Molecular and functional characterization of genotypic revertants. Clin Immunol. Jan 31 2010;[Medline].
Snapper SB, Meelu P, Nguyen D, Stockton BM, Bozza P, Alt FW. WASP deficiency leads to global defects of directed leukocyte migration in vitro and in vivo. J Leukoc Biol. Jun 2005;77(6):993-8. [Medline].
Morales-Tirado V, Sojka DK, Katzman SD, Lazarski CA, Finkelman FD, Urban JF, et al. Critical requirement for the Wiskott-Aldrich syndrome protein in Th2 effector function. Blood. Dec 23 2009;[Medline].
Notarangelo LD, Miao CH, Ochs HD. Wiskott-Aldrich syndrome. Curr Opin Hematol. Jan 2008;15(1):30-6. [Medline].
Gulacsy V, Freiberger T, Shcherbina A, et al. Genetic characteristics of eighty-seven patients with the Wiskott-Aldrich syndrome. Mol Immunol. Feb 2011;48(5):788-92. [Medline].
Albert MH, Notarangelo LD, Ochs HD. Clinical spectrum, pathophysiology and treatment of the Wiskott-Aldrich syndrome. Curr Opin Hematol. Nov 11 2010;[Medline].
Kwan SP, Hagemann TL, Blaese RM, Rosen FS. A high-resolution map of genes, microsatellite markers, and new dinucleotide repeats from UBE1 to the GATA locus in the region Xp11.23. Genomics. Sep 1 1995;29(1):247-52. [Medline].
Snapper SB, Rosen FS. The Wiskott-Aldrich syndrome protein (WASP): roles in signaling and cytoskeletal organization. Annu Rev Immunol. 1999;17:905-29. [Medline].
Anton IM, Jones GE. WIP: a multifunctional protein involved in actin cytoskeleton regulation. Eur J Cell Biol. Apr 2006;85(3-4):295-304. [Medline].
Konno A, Kirby M, Anderson SA, Schwartzberg PL, Candotti F. The expression of Wiskott-Aldrich syndrome protein (WASP) is dependent on WASP-interacting protein (WIP). Int Immunol. Feb 2007;19(2):185-92. [Medline].
Soderling SH, Scott JD. WAVE signalling: from biochemistry to biology. Biochem Soc Trans. Feb 2006;34(Pt 1):73-6. [Medline].
Takenawa T, Suetsugu S. The WASP-WAVE protein network: connecting the membrane to the cytoskeleton. Nat Rev Mol Cell Biol. Jan 2007;8(1):37-48. [Medline].
Perry GH, Spector BD, Schuman LM. The Wiskitt-Aldrich syndrome inthe United States and Canada. J Pediatr. 1980;97:72.
Ryser O, Morell A, Hitzig WH. Primary immunodeficiencies in Switzerland: first report of the national registry in adults and children. J Clin Immunol. Nov 1988;8(6):479-85. [Medline].
Abuzakouk M, Feighery C. Primary immunodeficiency disorders in the Republic of Ireland: first report of the national registry in children and adults. J Clin Immunol. Jan 2005;25(1):73-7. [Medline].
Mullen CA, Anderson KD, Blaese RM. Splenectomy and/or bone marrow transplantation in the management of the Wiskott-Aldrich syndrome: long-term follow-up of 62 cases. Blood. Nov 15 1993;82(10):2961-6. [Medline]. [Full Text].
Kobayashi R, Ariga T, Nonoyama S, Kanegane H, Tsuchiya S, Morio T. Outcome in patients with Wiskott-Aldrich syndrome following stem cell transplantation: an analysis of 57 patients in Japan. Br J Haematol. Nov 2006;135(3):362-6. [Medline].
Parolini O, Ressmann G, Haas OA, Pawlowsky J, Gadner H, Knapp W. X-linked Wiskott-Aldrich syndrome in a girl. N Engl J Med. Jan 29 1998;338(5):291-5. [Medline].
Peacocke M, Siminovitch KA. Wiskott-Aldrich syndrome: new molecular and biochemical insights. J Am Acad Dermatol. Oct 1992;27(4):507-19. [Medline].
Chandrakasan S, Singh S, Dogra S, Delaunay J, Proust A, Minz RW. Wiskott-Aldrich syndrome presenting with early onset recurrent acute hemorrhagic edema and hyperostosis. Pediatr Blood Cancer. Jul 1 2011;56(7):1130-2. [Medline].
Ochs HD, Thrasher AJ. The Wiskott-Aldrich syndrome. J Allergy Clin Immunol. Apr 2006;117(4):725-38; quiz 739. [Medline].
Thrasher AJ. New insights into the biology of Wiskott-Aldrich syndrome (WAS). Hematology Am Soc Hematol Educ Program. 2009;132-8. [Medline].
Kang HJ, Shin HY, Ko SH, et al. Unrelated bone marrow transplantation with a reduced toxicity myeloablative conditioning regimen in Wiskott-Aldrich syndrome. J Korean Med Sci. Feb 2008;23(1):146-8. [Medline].
Dupre L, Marangoni F, Scaramuzza S, et al. Efficacy of gene therapy for Wiskott-Aldrich syndrome using a WAS promoter/cDNA-containing lentiviral vector and nonlethal irradiation. Hum Gene Ther. Mar 2006;17(3):303-13. [Medline].
Galy A, Roncarolo MG, Thrasher AJ. Development of lentiviral gene therapy for Wiskott Aldrich syndrome. Expert Opin Biol Ther. Feb 2008;8(2):181-90. [Medline].
Lacy CF, Armstrong LL, Goldman MP, Lance LL, eds. Drug Information Handbook 2008-2009. 16th ed. Cleveland, OH: Lexi-Comp Inc; 2008.
Hooper JA. Intravenous Immunoglobulins: Evolution of Commercial IVIG Preparations. Immunol Allergy Clin North Am. Nov 2008;28(4):765-78. [Medline].
Shah S. Pharmacy considerations for the use of IGIV therapy. Am J Health Syst Pharm. Aug 15 2005;62(16 Suppl 3):S5-11. [Medline].
Siegel J. The product: All intravenous immunoglobulins are not equivalent. Pharmacotherapy. Nov 2005;25(11 Pt 2):78S-84S. [Medline].
Kroger AT, Atkinson WL, Marcuse EK, Pickering LK. General recommendations on immunization: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. Dec 1 2006;55:1-48. [Medline]. [Full Text].
Recommendations of the Advisory Committee on Immunization Practices (ACIP): use of vaccines and immune globulins for persons with altered immunocompetence. MMWR Recomm Rep. Apr 9 1993;42:1-18. [Medline]. [Full Text].
Cianferoni A, Massaad M, Feske S, et al. Defective nuclear translocation of nuclear factor of activated T cells and extracellular signal-regulated kinase underlies deficient IL-2 gene expression in Wiskott-Aldrich syndrome. J Allergy Clin Immunol. Dec 2005;116(6):1364-71. [Medline].
Dam T, Danelishvili L, Wu M, Bermudez LE. The fadD2 Gene Is Required for Efficient Mycobacterium avium Invasion of Mucosal Epithelial Cells. J Infect Dis. Apr 15 2006;193(8):1135-42. [Medline].
de Saint Basile G, Lagelouse RD, Lambert N, et al. Isolated X-linked thrombocytopenia in two unrelated families is associated with point mutations in the Wiskott-Aldrich syndrome protein gene. J Pediatr. Jul 1996;129(1):56-62. [Medline].
Derry JM, Kerns JA, Weinberg KI, et al. WASP gene mutations in Wiskott-Aldrich syndrome and X-linked thrombocytopenia. Hum Mol Genet. Jul 1995;4(7):1127-35. [Medline].
Derry JM, Ochs HD, Francke U. Isolation of a novel gene mutated in Wiskott-Aldrich syndrome [published erratum appears in Cell 1994 Dec 2;79(5):following 922]. Cell. Aug 26 1994;78(4):635-44. [Medline].
Dupuis-Girod S, Medioni J, Haddad E, et al. Autoimmunity in Wiskott-Aldrich syndrome: risk factors, clinical features, and outcome in a single-center cohort of 55 patients. Pediatrics. May 2003;111(5 Pt 1):e622-7. [Medline]. [Full Text].
Eijkhout HW, van Der Meer JW, Kallenberg CG, et al. The effect of two different dosages of intravenous immunoglobulin on the incidence of recurrent infections in patients with primary hypogammaglobulinemia. A randomized, double-blind, multicenter crossover trial. Ann Intern Med. Aug 7 2001;135(3):165-74. [Medline]. [Full Text].
Imai K, Morio T, Zhu Y, et al. Clinical course of patients with WASP gene mutations. Blood. Jan 15 2004;103(2):456-64. [Medline]. [Full Text].
Lorenzi R, Brickell PM, Katz DR, et al. Wiskott-Aldrich syndrome protein is necessary for efficient IgG-mediated phagocytosis. Blood. May 1 2000;95(9):2943-6. [Medline]. [Full Text].
Lutskiy MI, Shcherbina A, Bachli ET, Cooley J, Remold-O'Donnell E. WASP localizes to the membrane skeleton of platelets. Br J Haematol. Oct 2007;139(1):98-105. [Medline].
Mullen CA, Anderson KD, Blaese RM. Splenectomy and/or bone marrow transplantation in the management of the Wiskott-Aldrich syndrome: long-term follow-up of 62 cases. Blood. Nov 15 1993;82(10):2961-6. [Medline].
Ochs HD, Rosen FS. The Wiskott-Aldrich syndrome. In: Ochs HD, Smith CIE, Puck J, eds. Primary Immunodeficiency Diseases: a Molecular and Genetic Approach. New York, NY: Oxford University Press; 1999:292-305.
Olivier A, Jeanson-Leh L, Bouma G, et al. A partial down-regulation of WASP is sufficient to inhibit podosome formation in dendritic cells. Mol Ther. Apr 2006;13(4):729-37. [Medline].
Rengan R, Ochs HD, Sweet LI, et al. Actin cytoskeletal function is spared, but apoptosis is increased, in WAS patient hematopoietic cells. Blood. Feb 15 2000;95(4):1283-92. [Medline]. [Full Text].
Samarin SN. WASP family proteins act between cytoskeleton and cellular signaling pathways. Biochemistry (Mosc). Dec 2005;70(12):1305-9. [Medline].
Tsuboi S, Nonoyama S, Ochs HD. Wiskott-Aldrich syndrome protein is involved in alphaIIbbeta3-mediated cell adhesion. EMBO Rep. Mar 31 2006;[Medline].
Tsuji Y, Imai K, Kajiwara M, et al. Hematopoietic stem cell transplantation for 30 patients with primary immunodeficiency diseases: 20 years experience of a single team. Bone Marrow Transplant. Mar 2006;37(5):469-77. [Medline].
Wietstruck PMA, Zuniga CP, Talesnik GE, Mendez RC, Barriga CF. [Hematopoietic stem cell transplantation for patients with Wiskott-Aldrich syndrome]. Rev Med Chil. Jul 2007;135(7):917-23. [Medline].
| Brand(Manufacturer) | Manufacturing Process | pH | Additives (IVIG products containing sucrose are more often associated with renal dysfunction, acute renal failure, and osmotic nephrosis, particularly with preexisting risk factors [eg, history of renal insufficiency, diabetes mellitus, age >65 y, dehydration, sepsis, paraproteinemia, nephrotoxic drugs].) | Parenteral Form and Final Concentrations | IgA Content mcg/mL |
| Carimune NF (CSL Behring) | Kistler-Nitschmann fractionation; pH 4 incubation, nanofiltration | 6.4-6.8 | 6% solution: 10% sucrose, < 20 mg NaCl/g protein | Lyophilized powder 3%, 6%, 9%, 12% | Trace |
| Flebogamma (Grifols USA) | Cohn-Oncley fractionation, PEG precipitation, ion-exchange chromatography, pasteurization | 5.1-6 | Sucrose free, contains 5% D-sorbitol | Liquid 5% | < 50 |
| Gammagard Liquid 10% (Baxter Bioscience) | Cohn-Oncley cold ethanol fractionation, cation and anion exchange chromatography, solvent detergent treated, nanofiltration, low pH incubation | 4.6-5.1 | 0.25M glycine | Ready-for-use Liquid 10% | 37 |
| Gamunex (Talecris Biotherapeutics) | Cohn-Oncley fractionation, caprylate-chromatography purification, cloth and depth filtration, low pH incubation | 4-4.5 | Contains no sugar, contains glycine | Liquid 10% | 46 |
| Gammaplex (Bio Products) | Solvent/detergent treatment targeted to enveloped viruses; virus filtration using Pall Ultipor to remove small viruses including nonenveloped viruses; low pH incubation | 4.8-5.1 | Contains sorbitol (40 mg/mL); do not administer if fructose intolerant | Ready-for-use solution 5% | < 10 |
| Iveegam EN (Baxter Bioscience) | Cohn-Oncley fraction II/III; ultrafiltration; pasteurization | 6.4-7.2 | 5% solution: 5% glucose, 0.3% NaCl | Lyophilized powder 5% | < 10 |
| Polygam S/D Gammagard S/D (Baxter Bioscience for the American Red Cross) | Cohn-Oncley cold ethanol fractionation, followed by ultracentrafiltration and ion exchange chromatography; solvent detergent treated | 6.4-7.2 | 5% solution: 0.3% albumin, 2.25% glycine, 2% glucose | Lyophilized powder 5%, 10% | < 1.6 (5% solution) |
| Octagam (Octapharma USA) 9/24/10: Withdrawn from market because of unexplained reports of thromboembolic events | Cohn-Oncley fraction II/III; ultrafiltration; low pH incubation; S/D treatment pasteurization | 5.1-6 | 10% maltose | Liquid 5% | 200 |
| Panglobulin (Swiss Red Cross for the American Red Cross) | Kistler-Nitschmann fractionation; pH 4, trace pepsin, nanofiltration | 6.6 | Per gram of IgG: 1.67 g sucrose, < 20 mg NaCl | Lyophilized powder 3%, 6%, 9%, 12% | 720 |
| Privigen Liquid 10% (CSL Behring) | Cold ethanol fractionation, octanoic acid fractionation, and anion exchange chromatography; pH 4 incubation and depth filtration | 4.6-5 | L-proline (~250 mmol/L) as stabilizer; trace sodium; does not contain carbohydrate stabilizers (eg, sucrose, maltose) | Ready-for-use liquid 10% | ≤ 25 |

