Mutation analysis of WASP gene and prenatal diagnosis of Wiskott-Aldrich syndrome / 中华儿科杂志

<p><b>OBJECTIVE</b>Wiskott-Aldrich syndrome (WAS) is a rare X-linked primary immunodeficiency characterized by microthrombocytopenia, eczema, recurrent infections, and an increased incidence of autoimmunity and malignancies. The patients always have a severe clinical phenotype that can result in death if not diagnosed and treated early in life. The treatment of choice with the best outcome is hematopoietic stem cell transplantation, preferably from a matched related donor. But uncertain treatment effect and high treatment cost limit its clinical application. It is the best strategy that avoiding birth of a fetus with defect through prenatal diagnosis at present. This study aimed to analyze the mutation of WASP gene in 4 Chinese families with WAS and to provide prenatal diagnosis for the high-risk fetus.</p><p><b>METHOD</b>The probands of the four WAS families were all males, one of whom was deceased but had a family history and clinical datas integrated. All the patients were detected with blood routine tests, immunological tests and bone marrow examination. PCR and bilateral direct sequencing of PCR product was carried out in the regions of exon and exon-intron boundaries of WASP gene for 3 probands, 4 mothers and 100 unrelated healthy individuals as control. Prenatal diagnosis was provided for the two fetuses at the first trimester by mutation analysis.</p><p><b>RESULT</b>Four WASP gene mutations were detected: c.91A > G (p.E31K), c.665C > T (p.R211X), c.397G > A (p.E133K), c.952-953delCC (p. P317fsX18), among which c.952-953delCC (p. P317fsX18) was first reported. Mothers in Family 2, 3 and 4 were carriers of WASP gene mutation, but family 1 was considered as a de-novo mutation. None of the 100 unaffected subjects had the above mutants. Prenatal diagnosis indicated that the fetus in family 2 was male and carried the same mutation as the proband, so the fetus was presumably to be a patient. The parents decided to receive an induced abortion. Following the termination of the pregnancy, the result of gene analysis of the aborted tissues was consistent with prenatal diagnosis. The fetus in family 3 was normal male confirmed by normal test results six months after birth.</p><p><b>CONCLUSION</b>The 4 mutations of the WASP gene probably were causative to the families of WAS, among which c.952-953delCC was reported for the first time. Prenatal diagnosis by DNA sequencing is the effective method to avoid birth of WAS patient.</p>

Mutation analysis and prenatal diagnosis of a Chinese family with X-linked severe combined immunodeficiency / 中华儿科杂志

<p><b>OBJECTIVE</b>To analyze the mutation of IL2RG gene in a Chinese family with a birth history of a dead child suspected of X-linked severe combined immunodeficiency (X-SCID), and to perform prenatal diagnosis with DNA sequencing.</p><p><b>METHOD</b>Blood samples of the parents of the dead child and chorionic villi at gestational age 11 weeks were collected. Eight exons comprising the open reading frame as well as their exon/intron boundaries of IL2RG gene were analyzed by PCR and bi-directional sequencing.</p><p><b>RESULT</b>A heterozygous nucleotide substitution c.690C > T (R226C) in exon 5 was detected in the mother, but not in the father. In the second pregnancy of the mother, the mutation of R226C was not detected in the male fetus by prenatal diagnosis, and the heterozygous mutation was detected in the female fetus of the third pregnancy. The reliability of the prenatal genetic diagnosis was confirmed by the one-year follow-up after the neonates were born.</p><p><b>CONCLUSION</b>The mutation of c.690C>T in IL2RG gene may be the pathologic cause of the proband with X-SCID. DNA sequencing combining sex determination is a valid strategy for prenatal diagnosis of X-SCID.</p>

Síndrome de Wiskott-Aldrich / Wiskott - Aldrich syndrome

Objetivo: Descrever um caso de síndrome de Wiskott-Aldrich, enfatizandoa importância do diagnóstico precoce de uma imunodeficiênciarara, para seu tratamento adequado.Descrição do caso: Criança do sexo masculino, que aos seismeses de idade apresentou eczema em face e pescoço. Três mesesapós, evoluiu com piora, sendo internado com infecção secundária doeczema. Aos dez meses foi novamente internado por otite média comsecreção sanguinolenta, sangramento oral e lesões em pele com sufusõeshemorrágicas. Com um ano foi internado pela terceira vez, devidoà diarreia sanguinolenta, evoluindo com sepse. Exames laboratoriaisevidenciaram plaquetopenia e anemia, além de número reduzido delinfócitos T CD4+ e CD8+. A pesquisa para proteína da síndrome deWiskott-Aldrich foi ausente.Discussão: A Síndrome de Wiskott-Aldrich (WAS) é uma imunodeficiênciarara, ligada ao X, com manifestações clínicas característicasque incluem trombocitopenia com plaquetas pequenas, eczema, infecçõesrecorrentes e incidência aumentada de manifestações autoimunese malignidades. O diagnóstico precoce é muito importante para umtratamento adequado. Até o momento, a única terapia curativa é otransplante de células tronco.

Objective: Describe a case of Wiskott-Aldrich syndrome, emphasizingthe importance of early diagnosis of a rare immunodeficiency, for itsappropriate treatment.Case description: Male child, who at six months of age presentedeczema in face and neck. Three months later, progressed to worse,being admitted with secondary infection of the eczema. At ten monthswas again hospitalized due to otitis media with drainage of blood, oralbleeding and skin lesions with hemorrhagic suffusions. With one yearold was hospitalized for the third time, due to bloody diarrhea, evolvingto sepsis. Laboratory tests showed anemia and thrombocytopenia, andreduced number of CD4 and CD8 T lymphocytes. The search for theWiskott-Aldrich syndrome protein was absent.Discussion: The Wiskott-Aldrich Syndrome (WAS) is a rareimmunodeficiency, X-linked, with clinical features that includethrombocytopenia with small platelets, eczema, recurrent infections andincreased incidence of autoimmune manifestations and malignancies.Early diagnosis is very important for appropriate treatment. So far, theonly curative therapy is the transplantation of stem cells.

Neutropenia associated with X-linked agammaglobulinemia in an Iranian referral center

X-linked Agammaglobulinemia [XLA] is a hereditary immunodeficiency, characterized by an early onset of recurrent bacterial infections, hypogammaglobulinemia and markedly reduced B lymphocytes number. In order to determine the association of neutropenia among Iranian patients with XLA, hospital records of 30 patients with confirmed XLA in Children Medical Center Hospital, were reviewed. Eight out of 30 XLA patients [26.7%] developed neutropenia during the course of the disease. In two patients, episodes of neutropenia were identified before or at the time of diagnosis of XLA. Other six patients whom were not visited regularly and did not receive periodical immunoglobulin replacement therapy experienced neutropenia after diagnosis of XLA. Neutropenia in XLA is mainly associated with infection and is resolved with intravenous immunoglobulin replacement and antibiotics therapy

Combating oncogene activation associated with retrovirus-mediated gene therapy of X-linked severe combined immunodeficiency

A successful gene therapy clinical trial that also encountered serious adverse effects has sparked extensive study and debate about the future directions for retrovirus-mediated interventions. Treatment of X-linked severe combined immunodeficiency with an oncoretrovirus harboring a normal copy of the gc gene was applied in two clinical trials, essentially curing 13 of 16 infants, restoring a normal immune system without the need for additional immune-related therapies. Approximately 3 years after their gene therapy, tragically, 3 of these children, all from the same trial, developed leukemia as a result of this experimental treatment. The current understanding of the mechanism behind this leukemogenesis involves three critical and cooperating factors, i.e., viral integration, oncogene activation, and the function of the therapeutic gene. In this review, we will explore the causes of this unwanted event and some of the possibilities for reducing the risk of its reoccurrence.

A case of Wiskott-Aldrich syndrome

Wiskott-Aldrich syndrome is an X-linked combined immunodeficiency disorder characterized by severely decreased number of platelets which are small in size, eczema resembling atopic dermatitis and recurrent infection. The serum of the patient contains elevated concentrations of IgA and IgE, whereas the IgG level is usually normal and IgM level is decreased. The patients also shows skin test anergy and progressive T-lymphocytopenia. Bleedings and recurrent infections are the main causes of death and the patients usually die before age 10. Bone marrow transplantation is accepted to be the only radical therapy. We experienced a case compatible with Wiskott-Aldrich syndrome in a 5 year old male child who accompanied above clinical manifestations and laboratory findings.