Yukiji Yamada

Treatment of MPS VII (Sly disease) by allogeneic BMT in a female with homozygous A619V mutation

A 12-year-old girl with Sly disease (mucopoly- saccharidosis VII; β-glucuronidase deficiency), who is homozygous for the A619V mutation, had a successful allogeneic BMT, donored by an HLA-identical unrelated female to replace the deficient enzyme. Within 5 months after BMT, the enzyme activity of the recipient’s lymphocytes increased to normal range. No signs of acute or chronic GVHD were observed. For the successive 31 months post-BMT, β-glucuronidase activity in her lymphocytes was maintained at almost normal levels and excretion of glycosaminoglycans in the urine was greatly diminished. Ultrastructural findings demonstrated no abnormal vacuoles and inclusion bodies in the cytoplasm of her rectal mucosal cells. Coincident with the restoration of the enzyme activity, clinical improvement was dramatic. Especially notable were improvements in motor function. The patient was able to walk alone for a long time without aid, and she even became able to ride a bicycle and take a bath. In addition, recurrent infections of the upper respiratory tract and the middle ears decreased in frequency and severity, and dyspnea on exertion, severe snoring and vertigo have substantially improved. Thus, allogeneic BMT in this patient produced a better quality of life and provided a more promising outlook.

Mutation analysis in the iduronate-2-sulphatase gene in 43 Japanese patients with mucopolysaccharidosis type II (Hunter disease).

Our series of studies on Hunter disease in Japanese patients showed allelic heterogeneity of IDS gene mutations, genotype/phenotype correlation and racial differences in distribution of mutations. Twenty-five different small mutations have been characterized. Small mutations in the Japanese population are widely distributed through the IDS gene, although some mutations were unevenly concentrated on exon 5 (28%) and on exon 9 (24%). Mutations were seen at the same codon 468 in exon 9 in 5 patients. These findings are in good agreement with data on other ethnic groups. Two unique mutations linked to a severe phenotype were apparently associated with aberrant splicings; one was a point mutation within exon 3 (P86L), partially activating a cryptic splice acceptor site at 28 bp downstream from the mutation site within exon 3 and producing a 44-base truncated mRNA, and the other was a point mutation at the consensus sequence of the splice donor site of intron 2, causing exon 2 skipping.

Molecular basis of mucopolysaccharidosis type VII: replacement of Ala619 in β-glucuronidase with Val

We have identified a mutation causing beta-glucuronidase (beta Gl) deficiency in a 6-year-old girl with mucopolysaccharidosis type VII. Enzyme assay of lysates of a girls lymphocytes or cultured fibroblasts showed little residual activity and a normal beta Gl-specific mRNA level, as revealed by Northern-blot analysis. Sequencing of the full-length mutated cDNA revealed a C----T transition, an event causing a single Ala619----Val change (we designated this variant beta GGifu). This change is detected by loss of the cleavage site for the enzyme Fnu4HI in the mutated cDNA. On the basis of the loss of Fnu4HI restriction site, the patient was shown to be a homozygote with the beta GGifu mutation and her parents and brother were heterozygotes. This mutation disrupts a functional domain consisting of a region of sequence highly conserved among human, rat and bacterial beta Gls, and it reduces the enzyme activity, as tested by transfection of COS cells with expression vectors harboring the mutated cDNA.

Intermediate form of mucopolysaccharidosis type II (Hunter disease) : a C1327 to T substitution in the iduronate sulfatase gene

Hunter disease, an X-linked recessive lysosomal storage disorder, is caused by a deficiency in iduronate sulfatase activity. Sequence analysis of mRNA of fibroblasts of an intermediate phenotype patient showed a single C1327 to T nucleotide transition. This mutation resulted in a substitution of termination codon for normal arginine at position 443 of the peptide sequence. Expression studies with this abnormal cDNA in fibroblasts from the patient revealed a loss of enzymatic activity and instability of the mutated protein. We posturate that this mutation is probably the cause of the intermediate form of Hunter disease.

Mucopolysaccharidosis type II (Hunter disease): 13 gene mutations in 52 Japanese patients and carrier detection in four families

Southern blot analysis of the iduronate sulfatase (IDS) gene in 52 unrelated Japanese patients with mucopolysaccharidosis type II was carried out using a cDNA probe, and mutations in 13 patients (25%) were identified. Of these, 3 had partial gene deletions (in 2 the normal 9.4-kb fragment was absent and in 1 the normal 7.4-kb fragment was absent, as determined by Southern blot analysis using EcoRI-digested DNA, respectively), 2 had gene insertions (in 1 there was a unique 11.2kb fragment and in the other there was a unique 5kb fragment, determined by Southern blot analysis using EcoRI digested DNA), and 8 had rearrangements (in 6 the normal 9.4kb and 7.0kb fragments were absent and a unique 11.2kb fragment was present; in the remaining 2 patients there were different rearrangements). In these 13 patients, the similar Southern blot patterns were indicative of structural alterations of the IDS gene, as revealed when their DNA was digested with HindIII or PstI and probed with IDS cDNA. All patients with these structural alterations were in a clinically severe state, except for 1 with an intermediate clinical phenotype. Our analyses of four families among those of the 13 patients revealed that all four mothers were carriers. The detection of structural abnormalities led to a precise identification of Hunter heterozygotes and revealed one de novo rearrangement in a germ cell of one of the maternal grandparents.

Microsatellite instability in B-cell lymphoma originating from Bloom syndrome.

Bloom syndrome (BS) is a rare autosomal recessive genetic disorder characterized by lupus‐like erythematous telangiectasias of the face, sun sensitivity, stunted growth infertility and immunodeficiency. In addition, BS patients are highly predisposed to cancers. Although recently the causative gene of BS (BLM) was identified as a DNA helicase homologue, the function of BLM in DNA replication has not been elucidated. In this study, p53 mutation and microsatellite instability in B‐cell lymphomas originating from 2 sibling BS patients were investigated. In the originally developed tumor of both patients, no p53 mutation was detected. In one patient, however, after treatment by ionizing radiation the B‐cell lymphoma recurred, showing a 9‐bp deletion in exon 7. In lymphoma cells and an EB‐virus‐transformed cell line from BS lymphocytes of this patient, microsatellite instability was also detected from the reduced length of microsatellite DNA markers, although in the other patient microsatellite instability was not detected. Thus, 2 B‐cell lymphomas, despite having the same BLM mutation, showed different phenotypes in terms of p53 mutation and microsatellite instability.

Ataxia telangiectasia associated with B-cell lymphoma : The effect of a half-dose of the drugs administered according to the acute lymphoblastic leukemia standard risk protocol

Ataxia telangiectasia (A-T) is a rare autosomal recessive disorder characterized by cerebellar ataxia, oculocutaneous telangiectasia, and variable degrees of humoral and cellular immunodeficiency. Affected individuals are known to exhibit a high incidence of lymphoma and leukemia. Because of increased chemosensitivity, the treatment of A-T patients with malignancies requires extremely careful planning and caution with respect to the use of chemotherapy. The authors report on a 12-year-old boy with A-T who developed B-cell lymphoma. He received a half-dose of the drugs administered according to the acute lymphoblastic leukemia (ALL) protocol issued by our childrens cancer study group (9104 Standard Risk Protocol, Tokai Pediatric Oncology Study Group). As a result, he continues to be in complete remission and free of treatment complications 32 months after the diagnosis of B-cell lymphoma.

Suppressive effects of elimination diets on T cell responses to ovalbumin in hen's egg‐sensitive atopic dermatitis patients

We investigated the effect of elimination diets on T cell responses to ovalbumin (OA) in hens egg‐sensitive atopic dermatitis (AD) patients. The proliferative responses of both peripheral blood mononuclear cells (PBMCs) and T cells with monocytes to OA decreased after elimination diets, but those to Candida albicans or phytohemagglutinin (PHA) did not decrease after elimination diets. The proliferative responses of CD4+ T cells with monocytes to OA decreased after elimination diets. In these patients, clinical symptoms of AD improved. These results indicate that T cells, especially CD4+ T cells, respond to food antigens in food‐specific lymphocyte responses, and that elimination diets may be able to initiate reduction of the responsiveness of food‐sensitive T cells, especially CD4+ T cells. Moreover, the surface marker phenotypes of the T cells responding to OA were analysed. Our results showed that CD4+CD45RA+ T cells tended to increase. The increase in circulating CD4+CD45RA+ T cells might function as systemic suppression against immune responses in the skin.

Marinesco-Sjögren syndrome associated with acute mveloblastic leukemia

Marinesco‐Sjögren syndrome is a rare autosomal recessive disorder characterized by cerebellar atrophy, ataxia, cataracts, short stature and varying degrees of mental retardation. A high incidence of malignant disease associated with this syndrome has not so far been reported. We report the case of a 6‐year‐old girl affected with Marinesco‐Sjögren syndrome, who developed acute myeloblastic leukemia (AML, M2), and whose karyotype was 46,XX,t(8;21),(q22;q22) in bone marrow blasts. This is the first report of Marinesco‐Sjögren syndrome associated with malignant disorders.

Fatal transfusion‐associated graft‐versus‐host disease

Smith DK, Neal JJ, Holmberg SD. Unexplained opportunistic infections and CD4+ T-lymphocytopenia without HIV infection. An investigation of cases in the United States. N Engl J Med 1993;328:373-9. Spira TJ, Jones BM, Nicholson JK, et al. Idiopathic CD4+ Tlymphocytopenia. An analysis of five patients with unexplained opportunistic infections. N Engl J Med 1993;328:386-92. Lawrence J. T-cell subsets in health, infectious disease, and idiopathic CD4+ T-lymphocytopenia. Ann Intern Med