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X-linked agammglobulinemia (XLA) is a ptototypical humoral immunodeficiency caused by mutations in the gene coding for Bruton tyrosine kinase (BTK). The genetic defect in XLA impairs early B cell development resulting in marked reduction of mature B cells in the blood. Studies from different countries have demonstrated that approximately 90% of males with presumed XLA bear mutations in BTK. In this study, we report for the first time the occurrence of BTK mutations in Turkey. We performed mutational analysis of the BTK gene in 16 Turkish male patients from 13 separate families with presumed XLA based on abnormally low peripheral blood B-cell numbers (lt; 1%), hypogammaglobulinemia, and recurrent bacterial infections. We found that in nine of the 13 families (69%) a Btk mutation caused XLA. Two of the mutations were previously described, but seven novel mutations were identified: two missense (Y39C, G584R), one nonsense (Q343X), and 4 deletions (1800-1821del, 1843-1847del, 1288-1292del, 291del) resulting in frameshift and premature stop codon. By contrast, no mutations in the BTK gene were identified in the other 4 families. A consanguinity in three of these families raises the possibility that mutations in other autosomal genes which affect early B cell development may contribute to their phenotype resembling XLA., (Copyright 2001 Wiley-Liss, Inc.)

Wiskott-Aldrich syndrome (WAS) is a rare immune deficiency disease. Sialophorin glycosylation is defective in WAS. Although it is not very common, renal involvement including IgA nephropathy (IgAN) was reported. Abnormal glycosylation plays a key role in the pathogenesis of IgAN. We present an 8-year-old boy with WAS who had recurrent episodes of Henoch-Schönlein purpura with renal involvement following upper respiratory tract infections. His renal function did not deteriorate. Both IgAN and WAS have glycosylation defects, but there must be some other factors (genetic and environmental) to explain their rare association.

The V(D)J recombination process insures the somatic diversification of immunoglobulin and antigen T cell receptor encoding genes. This reaction is initiated by a DNA double-strand break (dsb), which is resolved by the ubiquitously expressed DNA repair machinery. Human T-B-severe combined immunodeficiency associated with increased cellular radiosensitivity (RS-SCID) is characterized by a defect in the V(D)J recombination leading to an early arrest of both B and T cell maturation. We previously mapped the disease-related locus to the short arm of chromosome 10. We herein describe the cloning of the gene encoding a novel protein involved in V(D)J recombination/DNA repair, Artemis, whose mutations cause human RS-SCID. Protein sequence analysis strongly suggests that Artemis belongs to the metallo-beta-lactamase superfamily.

Background: Transient hypogammaglobulinemia of infancy (THI) results from a delay in the maturation of immunoglobulin production., Methods: The clinical and immunologic data of 40 patients with THI are presented. Clinically, the majority of patients presented with recurrent respiratory infections and otitis media, bronchitis and/or bronchial asthma and recurrent gastroenteritis., Results: Ten of 40 children had isolated low IgG; isolated low IgA and isolated low IgM were detected in one and three patients, respectively. At initial evaluation, levels of all three immunoglobluins were low in nine patients. Ten patients had diminished IgG and IgA levels, six had diminished IgA and IgM levels and one had low IgG and IgM levels. Two patients were given intravenous immunoglobulin replacement therapy for 1 year. None of the patients has experienced serious infections during their follow-up period., Conclusions: Prospective evaluation of patients (age range 5-60 months) revealed that immunoglobulin levels in 33 patients recovered before 36 months of age. Seven patients still had low immunoglobluin levels at 40-57 months of age. Three of these patients had low levels of both IgG and IgA, while two patients had low IgM levels and a further two patients had low IgA levels.

The activation-induced cytidine deaminase (AID) gene, specifically expressed in germinal center B cells in mice, is a member of the cytidine deaminase family. We herein report mutations in the human counterpart of AID in patients with the autosomal recessive form of hyper-IgM syndrome (HIGM2). Three major abnormalities characterize AID deficiency: (1) the absence of immunoglobulin class switch recombination, (2) the lack of immunoglobulin somatic hypermutations, and (3) lymph node hyperplasia caused by the presence of giant germinal centers. The phenotype observed in HIGM2 patients (and in AID-/- mice) demonstrates the absolute requirement for AID in several crucial steps of B cell terminal differentiation necessary for efficient antibody responses.

Genetic lack of interleukin 12 receptor beta1 (IL-12Rbeta1) surface expression predisposes to severe infections by poorly pathogenic mycobacteria or Salmonella and causes strongly decreased, but not completely abrogated, interferon (IFN)-gamma production. To study IL-12Rbeta1-independent residual IFN-gamma production, we have generated mycobacterium-specific T cell clones (TCCs) from IL-12Rbeta1-deficient individuals. All TCCs displayed a T helper type 1 phenotype and the majority responded to IL-12 by increased IFN-gamma production and proliferative responses upon activation. This response to IL-12 could be further augmented by exogenous IL-18. IL-12Rbeta2 was found to be normally expressed in the absence of IL-12Rbeta1, and could be upregulated by IFN-alpha. Expression of IL-12Rbeta2 alone, however, was insufficient to induce signal transducer and activator of transcription (Stat)4 activation in response to IL-12, whereas IFN-alpha/IFN-alphaR ligation resulted in Stat4 activation in both control and IL-12Rbeta1-deficient cells. IL-12 failed to upregulate cell surface expression of IL-18R, integrin alpha6, and IL-12Rbeta2 on IL-12Rbeta1-deficient cells, whereas this was normal on control cells. IL-12-induced IFN-gamma production in IL-12Rbeta1-deficient T cells could be inhibited by the p38 mitogen-activated protein kinase (MAP) kinase inhibitor SB203580 and the MAP kinase kinase (MEK) 1/2 inhibitor U0126, suggesting involvement of MAP kinases in this alternative, Stat4-independent, IL-12 signaling pathway.Collectively, these results indicate that IL-12 acts as a partial agonist in the absence of IL-12Rbeta1. Moreover, the results reveal the presence of a novel IL-12Rbeta1/Stat4-independent pathway of IL-12 responsiveness in activated human T cells involving MAP kinases. This pathway is likely to play a role in the residual type 1 immunity in IL-12Rbeta1 deficiency.

Previous studies on a limited number of ataxia-telangiectasia (A-T) patients with detectable levels of intracellular ATM protein have suggested a genotype/phenotype correlation. We sought to elucidate this possible correlation by comparing ATM protein levels with mutation types, radiosensitivity, and clinical phenotype. In this study, Western blot analysis was used to measure ATM protein in lysates of lymphoblastoid cell lines (LCLs) from 123 unrelated A-T patients, 10 A-T heterozygotes, and 10 patients with phenotypes similar to A-T. Our Western blot protocol can detect the presence of ATM protein in as little as 1 microg of total protein; at least 25 microg of protein was tested for each individual. ATM protein was absent in 105 of the 123 patients (85%); most of these patients had truncating mutations. The remaining subset of 18 patients (15%) had reduced levels of normal-sized ATM protein; missense mutations were more common in this subset. We used a colony survival assay to characterize the phenotypic response of the LCLs to radiation exposure; patients with or without detectable ATM protein were typically radiosensitive. Nine of 10 A-T heterozygotes also had reduced expression of ATM, indicating that both alleles contribute to ATM protein production. These data suggest that although ATM-specific mRNA is abundant in A-T cells, the abnormal ATM protein is unstable and is quickly targeted for degradation. We found little correlation between level of ATM protein and the type of underlying mutation, the clinical phenotype, or the radiophenotype., (Copyright 2000 Academic Press.)

An analysis of polymorphism in the fourth component of human complement (C4) was performed on EDTA-plasma from 142 unrelated, randomly selected Turks without collagen-vascular disease or recurrent infections. Plasma samples treated with neuraminidase and carboxypeptidase-B were subjected to high-voltage agarose gel electrophoresis followed by immunofixation. C4B allotypes were further detected in some samples by Western blots with monoclonal antibody 1228 (anti-C4B/Ch1 reactivity). The frequencies of C4A and C4B alleles were determined. Allele C4B*5, which has been found to be relatively common in Asian (Oriental) populations, was not detected in this study. No specific predilection could be noted among the rare variants. C4A*3-C4B*1 was the most common haplotype (n = 40/142, or 28%) but was found less frequently than in Caucasian populations. This finding may be the result of the limited number of samples examined. C4A and/or C4B null allotypes were seen in 49 of 142 (34.6%) subjects. The most frequent C4 null allotype seen was C4B null (37/142, or 26%): 28 subjects had one C4B null allele; 1 had a homozygous deficiency of C4B (C4B*QO, *QO) and 7 had C4A*QO C4B*QO, a double heterozygous haplotype. Frequencies of homozygous haplotype C4A*Q0-C4B*Q0 in the population studied were found to be 0.007. The results of this study demonstrate that the genetic composition of the Turkish population exhibits both similarities and differences with the European population, and ranges between Caucasian and Mongoloid (Asian) populations.

Cyclic neutropenia is a rare disease characterized by regular cyclic fluctuations in the numbers of neutrophils. Patients with the disease suffer from recurrent infections at regular intervals of nearly three weeks. Recently, recombinant human granulocyte colony-stimulating factor (rhG-CSF) was reported to be an effective treatment for this disease. here we describe 17-year-old cyclic neutropenic female patient with a very rare association of renal amyloidosis of AA type who was under intermittent rhG-CSF treatment for the previous one and a half years. We conclude that although the disorder is usually benign, reactive amyloidosis may rarely develop in cases who remain untreated for a long period of time. However familial Mediterranean fever (FMF) type II should also be born in mind, particularly in predisposed populations.

MHC class II deficiency patients are mutated for transcription factors that regulate the expression of major histocompatibility complex (MHC) class II genes. Four complementation groups (A-D) are defined and the gene defective in group A has been shown to encode the MHC class II transactivator (CIITA). Here, we report the molecular characterization of a new MHC class II deficiency patient, ATU. Cell fusion experiments indicated that ATU belongs to complementation group A. Subsequent mutation analysis revealed that the CIITA mRNA lacked 84 nucleotides. This deletion was the result of the absence of a splice donor site in the CIITA gene of ATU. As a result of this novel homozygous genomic deletion, ATU CIITA failed to transactivate MHC class II genes. Furthermore, this truncated CIITA of ATU did not display a dominant negative effect on CIITA-mediated transactivation of various isotypic MHC class II promoters.

Griscelli disease (GD) is a rare disorder characterized by pigment dilution, immunodeficiency and occurrence of accelerated phase consisting of hemophagocytosis, pancytopenia and neurological manifestations. Allogeneic BMT in the early period is an important modality of treatment for GD. We carried out an alloBMT from an HLA-identical sibling donor on a 4-year-old girl who presented in accelerated phase with neurological manifestations including convulsions, strabismus, severe dysarthria, ataxia and clonus. She was treated with etoposide, methylprednisolone and intrathecal methotrexate for 8 weeks and underwent alloBMT after receiving a conditioning regimen including ATG (rabbit, 10 mg/kg x 5 days), Bu/Cy. 8 x 108/kg nucleated bone marrow cells were given. Engraftment occurred early and the post-BMT period was uneventful. Currently, she is at 18 months post BMT with sustained engraftment and with a normal neurological examination except for minimal clonus. Long-term follow-up will determine the prognosis regarding the neurological findings.

Chronic granulomatous disease (CGD) is a rare disorder of phagocytic cell oxidative metabolism. Patients have recurrent infections with catalase-positive organisms and granulomatous lesions throughout the body. Gastric antrum can be an occult site of involvement. We describe a four-year old boy with chronic granulomatous disease who was admitted with the complaints of persistent vomiting and weight loss. Gastric antral narrowing was diagnosed according to radiological findings. Treatment with steroid and antibiotics yielded a good clinical response in 15 days with a relief of the obstruction. This case report emphasizes the beneficial effect of this form of therapy in preventing life-threatening obstruction of vital organs in CGD.

A 12-year-old boy with common variable immunodeficiency (CVI) who developed severe alopecia is presented. His sister also had alopecia and recurrent infections and died of lung infection at the age of 7 years. The loss of hair in both children was total; the pathology of a scalp skin biopsy specimen was typical for alopecia areata. The boy was subjected to clinical and immunologic evaluation and the results were compatible with common variable immunodeficiency.

Mutations resulting in defective splicing constitute a significant proportion (30/62 [48%]) of a new series of mutations in the ATM gene in patients with ataxia-telangiectasia (AT) that were detected by the protein-truncation assay followed by sequence analysis of genomic DNA. Fewer than half of the splicing mutations involved the canonical AG splice-acceptor site or GT splice-donor site. A higher percentage of mutations occurred at less stringently conserved sites, including silent mutations of the last nucleotide of exons, mutations in nucleotides other than the conserved AG and GT in the consensus splice sites, and creation of splice-acceptor or splice-donor sites in either introns or exons. These splicing mutations led to a variety of consequences, including exon skipping and, to a lesser degree, intron retention, activation of cryptic splice sites, or creation of new splice sites. In addition, 5 of 12 nonsense mutations and 1 missense mutation were associated with deletion in the cDNA of the exons in which the mutations occurred. No ATM protein was detected by western blotting in any AT cell line in which splicing mutations were identified. Several cases of exon skipping in both normal controls and patients for whom no underlying defect could be found in genomic DNA were also observed, suggesting caution in the interpretation of exon deletions observed in ATM cDNA when there is no accompanying identification of genomic mutations.

Patients suffering from major histocompatibility complex (MHC) class II deficiency, a rare primary immunodeficiency, are characterized by a lack of MHC class II expression which is the result of defects in trans-acting factors. At least four complementation groups, A, B, C, and D, can be discerned. The gene affected in group C patients is known to be RFX5 and encodes one of the subunits of the multimeric phosphoprotein complex, RFX. In the present study we fused fibroblasts of a recently identified MHC class II deficiency patient, OSE, with fibroblasts derived from patients representative of each of the four complementation groups. Transient heterokaryon analysis indicated that OSE belonged to complementation group C. Furthermore, transfection of wild-type RFX5 cDNA into OSE fibroblasts resulted in restoration of the defect. Mutation analysis revealed that the RFX5 mRNA lacked four nucleotides and that this deletion was the consequence of a G to A transition in a splice acceptor site. Genomic oligotyping demonstrated that OSE was homozygous for the splice site mutation.

IgG2 antibody is the essential subclass to protect against encapsulated bacteria Fc gamma RIIa is the only Fc gamma receptor that interacts with human IgG2. The two genetically determined allotypes of human Fc gamma RIIa, Fc gamma RIIa-R131 and Fc gamma RIIa-H131 alleles have functionally different reactivities with IgG2 in vitro, and H/H-131 cells have markedly higher binding affinity for human IgG2. Homozygous Fc gamma RIIIb-NA1/NA1 PMNLs show higher phagocytic capacity than Fc gamma RIIIb-NA2/NA2 PMNLs. To evaluate in vivo significance of Fc gamma RIIa and Fc gamma RIIIb allotypes, we analyzed Fc gamma R allotypes in children with bacterial meningitis due to Haemophilus influenzae type b, Streptococcus pneumoniae and Neisseria meningitidis. Fc gamma RII and Fc gamma RIIIb polymorphisms were determined by using quantitative flow cytometry. Fc gamma RIIa were studied in 23 children with bacterial meningitis and 50 healthy Turkish controls, and Fc gamma IIIb in 18 and 43 such individuals, respectively. The distribution of Fc gamma RIIa in the healthy Turkish control group was found to be significantly different from that in the Chinese and Japanese population (p < 0.05), but similar to that of the white population in the USA and the Netherlands. No case (0%) had the Fc gamma RII-H/H-131 Fc gamma RIIIb-NA1/NA1 the corresponding figure in the controls was 4 (9.3%). Homozygous Fc gamma RIIa-H/H-131 phenotype was underrepresented with borderline significance (p: 0.057) in patients below two years of age in comparison with the healthy subjects and with patients with meningitis over two years of age (p: 0.059). Although the study needs to be conducted in a large series of patients in order to draw a firm conclusion, Fc gamma RIIa polymorphism may be a contributing factor to the increased susceptibility to meningitis with encapsulated bacteria in children below two years of age.

Ataxia-telangiectasia (A-T) is an autosomal recessive disorder characterized by neurodegeneration, immunodeficiency, cancer predisposition, and radiation sensitivity. The responsible gene, ATM, has an extensive genomic structure and encodes a large transcript with a 9.2 kb open reading frame (ORF). A-T mutations are extremely variable and most of them are private. We streamlined a high throughput protocol for the search for ATM mutations. The entire ATM ORF is amplified in a single RT-PCR step requiring a minimal amount of RNA. The product can serve for numerous nested PCRs in which overlapping portions of the ORF are further amplified and subjected to restriction endonuclease fingerprinting (REF) analysis. Splicing errors are readily detectable during the initial amplification of each portion. Using this protocol, we identified 5 novel A-T mutations and completed the elucidation of the molecular basis of A-T in the Israeli population.

Serum opsonization of yeast (Saccharomyces) was investigated in 51 patients whose ages were between six and 48 months (median 15 months) with acute purulent otitis media and in an age-matched control group (median 13 months). Opsonization was assessed by measuring yeast particle uptake in an assay based on an electronic count of the unphagocytosed particles in serum by polymorphonuclear leukocytes. Despite normal levels of CH50 and serum immunoglobulins, a defective opsonization was determined in 13.7 percent of the patients (7 in 51). The corresponding figure was 2.9 percent in 103 healthy controls (p < 0.001). On the other hand, 218 percent (5 in 23) of the children having a history of recurrent purulent otitis media showed defective opsonization (p < 0.001). Previously, the presence of an opsonization defect has been linked to low levels of mannan binding lectin (MBL), a calcium dependent serum lectin that acts as an opsonin. Therefore, our findings indirectly support the idea that MBL has an important role as host defense, particularly in the earlier period of life when the antibody repertoire is restricted.

We report the clinical and immunologic features and outcome in 56 patients with X-linked hyper-IgM syndrome, a disorder caused by mutations in the CD40 ligand gene. Upper and lower respiratory tract infections (the latter frequently caused by Pneumocystis carinii), chronic diarrhea, and liver involvement (both often associated with Cryptosporidium infection) were common. Many patients had chronic neutropenia associated with oral and rectal ulcers. The marked prevalence of infections caused by intracellular pathogens suggests some degree of impairment of cell-mediated immunity. Although lymphocyte counts and in vitro proliferation to mitogens were normal, a defective in vitro proliferative response to antigens was observed in some patients, and additional defects of cell-mediated immunity may be presumed on the basis of current knowledge of CD40-ligand function. All patients received regular infusions of immunoglobulins. Four patients underwent liver transplantation because of sclerosing cholangitis, which relapsed in there. Three patients underwent bone marrow transplantation. Thirteen patients (23%) died of infection and/or liver disease. X-linked hyper-IgM syndrome, once considered a clinical variant of hypogammaglobulinemia, is a severe immunodeficiency with significant cellular involvement and a high mortality rate.

Griscelli disease (OMIM 214450) is a rare autosomal recessive disorder characterized by pigmentary dilution, variable cellular immunodeficiency and onset of acute phases of uncontrolled lymphocyte and macrophage activation, leading to death in the absence of bone-marrow transplantation. The pigmentary dilution is characterized by a diffuse skin pigmentation, silvery hair, large clumps of pigments in the hair shafts (Fig. 1) and an accumulation of melanosomes in melanocytes, with abnormal transfer of the melanin granules to the keratinocytes. Immunological abnormalities are characterized by absent delayed-type cutaneous hypersensitivity and an impaired natural-killer cell function. A similar disorder has been described in the dilute lethal mouse--which, however, differs by the occurrence of a severe neurological disorder. The dilute locus encodes myosin-Va, a member of the unconventional myosin family. Myosins bind actin and produce mechanical force through ATP hydrolysis. Some members of this family are thought to participate in organelle-transport machinery. Because of the phenotype resulting in the dilute mouse and because of their potential role in intracellular transport, unconventional myosin-encoding genes were regarded as candidate genes for Griscelli disease. Here we report that the Griscelli disease locus co-localizes on chromosome 15q21 with the myosin-Va gene, MYO5a, and that mutations of this gene occur in two patients with the disease. Griscelli disease is therefore a human equivalent of dilute expression in the mouse.

X-linked hyper-IgM syndrome (X-HIM) is an immunodeficiency caused by mutations in the gene encoding the CD40 ligand (CD40L). A database (CD40Lbase) of CD40L mutations has now been established, and the resultant information, together with other mutations reported elsewhere in the literature, is presented here.

A 3.5 year old male patient with dyskeratosis congenita (DC) presented at the age of 13 months with isolated neutropenia preceding characteristic skin findings. The average absolute neutrophil count of 500/mm3 persisted without the presence of anemia or thrombocytopenia during the follow up. Neutropenia responded to granulocyte-colony stimulating factor (G-CSF) at a dose of 10 micrograms/kg per day. Immunologic findings were normal as was the chromosomal stability and sister chromatid exchange.

Deficiency in the second component of complement (C2) is the most common homozygous complement deficiency. While approximately half of the affected individuals are apparently healthy, C2 deficiency may be associated with autoimmune diseases and rarely increased susceptibility to infection. We report 5 patients who had homozygous type I C2 deficiency in two families. Three of them suffered from frequent infections. These symptomatic patients had additional risk factors; the index cases in the first and the second family had IgG2 deficiency and IgA deficiency, respectively, and alternative complement pathway hemolytic activity was also low in both of them and in the sibling of the first index case. These results emphasize the probable role of other immunologic defects in the clinical presentation of C2 deficiency.

Ataxia-telangiectasia (A-T) is an autosomal recessive disorder involving cerebellar degeneration, immunodeficiency, chromosomal instability, radiosensitivity and cancer predisposition. The responsible gene, ATM, was recently identified by positional cloning and found to encode a putative 350 kDa protein with a Pl 3-kinase-like domain, presumably involved in mediating cell cycle arrest in response to radiation-induced DNA damage. The nature and location of A-T mutations should provide insight into the function of the ATM protein and the molecular basis of this pleiotropic disease. Of 44 A-T mutations identified by us to date, 39 (89%) are expected to inactivate the ATM protein by truncating it, by abolishing correct initiation or termination of translation, or by deleting large segments. Additional mutations are four smaller in-frame deletions and insertions, and one substitution of a highly conserved amino acid at the Pl 3-kinase domain. The emerging profile of mutations causing A-T is thus dominated by those expected to completely inactivate the ATM protein. ATM mutations with milder effects may result in phenotypes related, but not identical, to A-T.

Isolated or combined deficiencies of immunoglobulin G (IgG) subclasses have been recognized in children with recurrent infections. In our allergy practice, there are a subset of children with recurrent respiratory tract infections. To investigate the presence of immunoglobulin G subclass deficiency (IgGSD), 60 children with atopy and 14 children without atopy suffering from recurrent respiratory tract infections were studied in an attempt to determine whether atopy is associated with a certain IgG subclass pattern. Ten atopic children were found to have isolated or combined IgG subclass deficiencies: one with IgG1, two with IgG2, four with IgG3 and three children had IgG2-IgG3. Neither IgG subclass concentration nor the frequency of children with high or low IgG subclasses showed any difference between atopic and non-atopic groups. Except for a week correlation with IgG3, no correlation existed between IgE and other IgG subclasses. It was concluded that childhood respiratory diseases complicated by recurrent respiratory tract infections may be associated with IgG subclass deficiencies. Although there have been reports noting some IgG subclass patterns in atopic disorders, in the present study, no distinctive feature between atopics and non-atopics with respect to IgG subclass concentrations and patterns was observed.

Low expression of T-cell receptor-CD3 (TCR-CD3) complex, a rare cause of combined immunodeficiency, has only recently begun to be recognized. Here we report a four-year-old boy who has defective TCR-CD3 complex expression presenting with recurrent chest infections and pulmonary symptoms implying bronchial asthma. In our opinion, this entity should be borne in mind as the possible underlying defect in children with combined immunodeficiency having signs and symptoms of humoral immunodeficiency.

Presented here is a 17-month-old adenosine deaminase-deficient, severe combined immunodeficient patient with chest symptoms, oral ulcer, neurologic manifestations, head lag, spasticity and developmental delay in motor functions. Antibiotics, systemic antifungal agents, intravenous immunoglobulins and partial exchange transfusions with irradiated fresh red cells were given. No other mode of therapy for adenosine deaminase (ADA) deficiency was available at that time. Amelioration of neurologic manifestations within one month of therapy with irradiated fresh red cell exchange transfusions suggests that these manifestations may have resulted from accumulated toxic metabolites. However, no improvement was seen in the course of infection and oral ulcer, and the patient died of respiratory failure on the 48th day of admission.

We report on a girl with selective IgA deficiency and persistently low complement component 4 (C4) levels compatible with heterozygous C4 deficiency. Deterioration of her serum immunoglobulin levels and transition to common variable immunodeficiency were observed within a 5 year follow-up. She also developed Sjögren's syndrome, autoimmune hemolytic anemia and immune thrombocytopenic purpura. While these abnormalities have been described before in various combinations, to our knowledge, they have not been reported in a single individual.

A gene, ATM, that is mutated in the autosomal recessive disorder ataxia telangiectasia (AT) was identified by positional cloning on chromosome 11q22-23. AT is characterized by cerebellar degeneration, immunodeficiency, chromosomal instability, cancer predisposition, radiation sensitivity, and cell cycle abnormalities. The disease is genetically heterogeneous, with four complementation groups that have been suspected to represent different genes. ATM, which has a transcript of 12 kilobases, was found to be mutated in AT patients from all complementation groups, indicating that it is probably the sole gene responsible for this disorder. A partial ATM complementary DNA clone of 5.9 kilobases encoded a putative protein that is similar to several yeast and mammalian phosphatidylinositol-3' kinases that are involved in mitogenic signal transduction, meiotic recombination, and cell cycle control. The discovery of ATM should enhance understanding of AT and related syndromes and may allow the identification of AT heterozygotes, who are at increased risk of cancer.

Bare lymphocyte syndrome (BLS) is a rare disorder characterized by deficient expression of human leukocyte antigens (HLA antigens) and combined immunodeficiency to various degrees. Recurrent severe infections especially due to opportunistic organisms are common. Here, we present two patients with BLS who lack both class I and II antigens (Type III). They had the typical clinical and immunologic findings of BLS. The first patient showed marked improvement in pulmonary symptoms resulting from cytomegalovirus infection by means of gancyclovir treatment. However, intramuscular injections of interferon-alpha (IFN-alpha) had no beneficial effect in either the expression of HLA antigens or the clinical status. The second patient died of septicemia while being prepared for bone marrow transplantation.

The genotyping data given localize the major A-T gene to an approximately 850 kb region. They also localize the group A A-T gene (ATA) to a region that contains the approximately 850 kb region. They are compatible with linking A-TFresno to 11q22-23. NBS-V2 does not link to this region. Four non-linking families contain only single affecteds, suggesting that these may be spontaneous mutations rather than evidence for an A-T gene outside the 11q22-23 region. Finally, two other non-linking families contain recombinant haplotypes that are compatible with a second A-T gene at 11q22-23, slightly distal to the approximately 850 kb region. However, convincing evidence for a second gene is still lacking.

A 2-month-old SCID patient with mesangial sclerosis of the kidney is presented. Although the ADA status of the patient is unknown, the parents' RBC-ADA levels seemed to be in the heterozygote range.

Major aphthous stomatitis (Sutton's disease) is a clinical variant of recurrent aphthous stomatitis, which is noted for its high morbidity. Since the etiology of the disease is not clear, many therapies have been attempted. However, the controversial results hinder the adoption of a single mode of management. We present a 13-year-old boy with Sutton's disease, who was successfully treated with a combination of burst systemic prednisone (1 mg/kg/day for five days, thereafter half dose on alternate days for one week) and topical triamcinolone (four rinses a day). He continued the mouth rinses with the same interval. At the end of the first month, significant healing was observed and gradual tapering was recommended on the condition that the ulcers were well-controlled. The maintenance of steroid rinse once a day provided a symptom-free period of one year. Neither any withdrawal signs nor side affects were observed. Therefore, we think that this regimen should be considered as the treatment of choice in Sutton's disease along with a close follow-up even in childhood.

Immunoglobulin G (IgG) subclass levels were determined in 393 serum samples of 329 healthy children from birth to 16 years of age, 24 healthy adults and 20 pairs of mother-cord blood by radial immunodiffusion. Age-normal percentile values for IgG1, IgG2 and IgG3 were calculated for age-groups up to 16 years and for adults. The broad range of IgG4 values in children did not permit calculation of reference values.

Along with clinical parameters, chemotaxis and random migration of neutrophils were evaluated in 15 patients with Down's syndrome (DS) and 15 healthy subjects. Signs of more severe gingival inflammation were present in the DS group. The random migration and chemotaxis of neutrophils were significantly decreased in comparison with the control group. In DS, the pathological status was attributed to these impaired host defense factors besides the existing bacterial plaque.

We present an autopsy case of neonatal miliary tuberculosis in a 36-day-old baby that was born to a mother who had no symptoms. Histopathological examination of lungs revealed necrosis and numerous acid-fast bacilli. Mycobacterium tuberculosis hominis was isolated by guinea pig inoculation with lung tissue. Three months after dietary the mother was admitted with pleural effusion and endometrial biopsy showed a granulomatous inflammation compatible with tuberculosis. Intrauterine infection was considered and that was supported by retrospective findings of the endometrial biopsy. We also want to emphasize the importance of searching for genital tuberculosis even if the mother has no symptoms.

Three siblings diagnosed as having Griscelli's syndrome (GS) are presented. The clinical features were partial albinism, silvery hair and absence of giant granules in the white blood cells. The diagnosis of GS was confirmed intra-vitam in the youngest sibling (propositis) at the age of nine months by the demonstration of irregular clumps of pigment in the hair shaft, and in particular melanocytes engorged with melanosomes in the skin biopsy, findings characteristic of this syndrome. A retrospective diagnosis of GS was made in the older two siblings. The first sibling died at the age of two, having a clinical picture suggestive of bulbar poliomyelitis. However, no tissue was available for histopathologic examination. The second sibling developed fever, jaundice, seizure, hepatosplenomegaly and lymphadenopathy and died at the age of six. Postmortem examination of this sibling revealed lymphohistiocytosis in the liver and spleen. The propositus died at the age of five following development of central nervous system involvement. Immunologic studies were not available in the first sibling. The IgG level was slightly low and the T-lymphocyte number was normal in the second sibling. The propositus had normal serum immunoglobulin levels and T-cell numbers and skin tests were positive with phytohemagglutinin and candida.

We evaluated nine patients with humoral immunodeficiency (6 immunodeficiency with hyper-IgM, 2 X-linked agammaglobulinemia, 1 common variable immunodeficiency) who were being treated with intravenous immunoglobulins (IVIG). After the use of the IVIG regimen in a dose of 250-300 mg/kg/4 weeks for one year, the severity and frequency of infections, even in patients with chronic lung disease, decreased significantly. An improvement in pulmonary function tests was observed in four patients who had airway obstruction prior to IVIG therapy. Side effects such as chills and fever were observed in 21 of 91 infusions, particularly in the early months of therapy. Preinfusion administration of aspirin and diphenhydramine prevented these side effects. The inversion of the CD4+/CD8+ ratio was detected in most patients during both intramuscular gammaglobulins (IMIG) and IVIG therapy.

To further pinpoint the location of the genes for ataxia-telangiectasia on the long arm of chromosome 11, we performed linkage analysis and analysis of recombinants of genetic haplotypes on 14 Turkish families with ataxia-telangiectasia, 12 of which were consanguineous. These studies used more than 25 polymorphic genetic markers spanning a region of the long arm of chromosome 11 that is larger than 50 cM. Seven markers gave significant LOD scores to AT: CJ5, DRD2, CJ208, S144, CD3E, PBGD, and S147, as did haplotypes created with pairs of markers DRD2/CJ5 and S144/CJ208, giving recombination fractions (theta) of 0.00, 0.00, 0.05, 0.08, 0.03, 0.09, 0.07, 0.00, and 0.06, respectively. Monte Carlo analysis of these 14 Turkish families indicated the best location for a single AT gene to be within a 6 cM sex-averaged (3 cM male-specific) interval defined by STMY and CJ77; this was three times more likely than the next most likely location (peak III) at the DRD2 locus. The analysis also revealed a peak (peak II) between S147 and S133, which may represent the complementation group D gene. Recombinant analysis of haplotypes also localized an AT locus to the STMY-CJ77 interval. Taken together, these results suggest that at least two distinct AT loci exist (ATA and ATD) at 11q22-23, with perhaps a third locus, ATC, located very near to the ATA gene. This genetic heterogeneity further complicates plans to isolate the major ATA and ATC genes and to begin identifying AT carriers in the general population.

We evaluated IgG subclass levels in 11 symptomatic patients (ages between 3 and 22; mean 7.5 years) with IgA deficiency, seven with selective IgA deficiency, and four with low IgA levels. All patients had experienced three or more episodes of sinopulmonary infections a year. Combined IgG2-IgG4 deficiency was detected in two patients, IgG2 deficiency in one patient and IgG4 deficiency in two patients. Elevated IgG1 and IgG3 levels were detected in most of the IgG subclass deficient and sufficient patients. It is known that gammaglobulin replacement therapy reduces the frequency of infections significantly in IgG subclass deficiency. Although immunization against IgA is a risk in IgA deficiency, these patients can be treated with gammaglobulins containing low IgA.

Linkage of at least two complementation groups of ataxia-telangiectasia (AT) to the chromosomal region 11q23 is now well established. We provide here an 18-point map of the surrounding genomic region, derived from linkage analysis of 40 CEPH families. On the basis of this map, 111 AT families from Turkey, Israel, England, Italy, and the United States were analyzed, localizing the AT gene(s) to an 8-cM sex-averaged interval between the markers STMY and D11S132/NCAM. A new Monte Carlo method for computing approximate location scores estimates this location as being at least 10(8) times more likely than the next most likely interval, with a support interval midway between STMY and D11S132 that is either 5.2 cM (sex-averaged and conservatively based on 3 lod scores from the maximum-location score) or 2.8 cM (male specific, based on a 2.72:1 interval-specific female-to-male distance ratio.

The clinical and immunological findings of 160 patients diagnosed over a period of twenty years as having ataxia-telangiectasia (AT) are presented. The study group composed of 68 females and 92 males were members of 117 families. The rate of parental consanguinity was 65 percent. The incidence of AT in 117 families was 36.6 percent. All patients had the characteristic facial and postural features of AT. The mean duration of follow-up of 160 patients was 6.35 years. Fifty patients had died during the follow-up (36 of pulmonary infections, 14 of malignancies). Somatic growth retardation was a prominent feature. Recurrent sinopulmonary infections were detected in 66 percent of patients. Two patients had hypothyroidism, one had diabetes mellitus, and one had both conditions. The incidence of malignancies was found to be 2.3 percent in the immediate relatives of the patients. The total lymphocyte count was low in 57 percent, and skin tests to PHA, candida, PPD and SK-SD were negative in 17.7%, 72.6%, 43.6%, and 78.2% of patients, respectively. In vitro blastogenic response to PHA was low in 61 percent of patients. The mean value of E-rosette formation was significantly lower than control values. Six patients had low serum IgG levels. The serum IgM level was high in 26.6 percent of patients and the IgA level was low or absent in 51.3 percent. There was no correlation between immune disturbance and duration of illness.

IgG subclass levels were studied in 12 children, aged between 2.5-12 years with recurrent respiratory tract infections. They did not have low IgG levels or IgA deficiency. We found combined deficiency of IgG2-IgG4 in one patient and selective IgG2 deficiency in another (16.6% of patients). These two patients had bronchiectasis due to recurrent severe pneumonia, however one patient with bronchiectasis had normal IgG subclass concentrations. Our IgG subclass-deficient patients who did not respond to prophylactic antibiotic therapy were given gammaglobulin therapy. IgG subclass deficiency should be considered in children with unexplained recurrent infections even in the presence of normal serum immunoglobulin levels.

Linkage analysis is a recombinant technology used for gene mapping. If two genetic loci segregate together in a pedigree more often than by random chance, they are said to be linked, that is they lie close on the same chromosome. What makes the detection of linkage between two markers on a chromosome possible, are the recombination events which occurred during meiosis. Thus, information can be obtained for the location of a mutant gene by using markers with known locations. Since the first published reports of linkage over thirty years ago, the use of the "lod score" method to determine the chromosomal location of a disease gene has become widespread. With the continual production of new RFLPs, the mapping of new loci will continue to become faster and more efficient. The power of the linkage method has spawned the development of several new techniques which utilize marker data to graphically represent the most likely location of a disease gene. Such advances, however, can best be utilized only after initial chromosomal localization of the particular gene through the lod score method.

We recently mapped the gene for ataxia-telangiectasia group A (ATA) to chromosome 11q22-23 by linkage analysis, using the genetic markers THY1 and pYNB3.12 (D11S144). The most likely order was cent-AT-S144-THY1. The present paper describes further mapping of the AT locus by means of a panel of 10 markers that span approximately 60 cM in the 11q22-23 region centered around S144 and THY1. Location scores indicate that three contiguous subsegments within the [S144-THY1] segment, as well as three contiguous segments telomeric to THY1, are each unlikely to contain the AT locus, while the more centromeric [STMY-S144] segment is most likely to contain the AT locus. These data, together with recent refinements in the linkage and physical maps of 11q22-23, place the AT locus at 11q23.

The clinical and immunologic features of six patients with X-linked agammaglobulinemia (XLA) are presented. The most common presenting manifestations were respiratory and gastrointestinal tract infections. On admittance to the hospital, one patient had a history of recurrent meningitis, another had a dermatomyositis-like syndrome, and still another had a history of recurrent arthritis.