Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0032285 (pneumonia)
 54,520 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Wiskott-Aldrich syndrome (WAS) is an X-linked recessive disorder characterized by microthrombocytopenia, eczema, immunodeficiency, and susceptibility to lymphoid malignancy. Loss-of-function mutations in WAS gene have been identified to cause disorders with platelet defects including WAS and X-linked thrombocytopenia. Mutations anticipated to yield truncated or no protein have been associated with the more severe presentations of WAS. Activating mutations in WAS gene result in an entirely different phenotype, an X-linked severe congenital neutropenia. We describe a Thai family with classic WAS. The proband, a one-year-old boy presented with recurrent mucous bloody diarrhea, recurrent otitis media, chronic eczema, thrombocytopenia, and small platelet sizes. The patient's older brother who also had persistent thrombocytopenia died at the age of seven months from severe pneumonia. Immunoblot analysis demonstrated that the proband's cells lacked WAS protein expression. Mutation analysis of the proband and his mother for the entire coding region of WAS identified a novel type of mutation, a termination codon mutation, X503R. The change is expected to result in an elongated mRNA that would code for a WASP of 581 amino acid residues instead of the normal 502 residues. Because of the absence of WASP expression, we speculate that the termination codon mutation causes reduced mRNA stability. Our findings supported that WAS mutations resulted in no protein are associated with a severe phenotype of WAS.
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PMID:A novel termination codon mutation of the WAS gene in a Thai family with Wiskott-Aldrich syndrome. 1461 70

The X-linked hyper-IgM (XHIGM) syndrome is an uncommon primary immunodeficiency disease caused by mutations in the gene for CD40 ligand and characterized by normal or elevated serum IgM, reduced levels of IgG and IgA, and defective T-cell function. Because of its rarity, it has been difficult for any single investigator or institution to develop a comprehensive clinical picture of this disorder. Accordingly, a national registry was developed in the United States to provide demographic, genetic, immunologic, and clinical information on a relatively large number of patients with the XHIGM syndrome.A total of 79 patients from 60 unrelated families were registered between January 1997 and July 2002. The estimated minimal incidence was approximately 1/1,030,000 live births. All of the patients had significant IgG deficiency and most had IgA deficiency, but only one-half had elevated IgM levels. Most patients presented initially with a history of an increased susceptibility to infection including Pneumocystis carinii pneumonia. The average age of diagnosis was significantly earlier in patients born into a family with a previously affected individual. However, only one-third of the patients born into a family with a previously affected individual were diagnosed exclusively because of the presence of the positive family history before any clinical symptoms developed. Over half the patients developed symptoms of immunodeficiency and were diagnosed by 1 year of age, and over 90% by 4 years of age. The most prominent clinical infections were pneumonia (81% of patients), upper respiratory infections (49%) including sinusitis (43%) and recurrent otitis (43%), recurrent/protracted diarrhea (34%), central nervous system infections (14%), sepsis (13%), cellulitis (13%), hepatitis (9%), and osteomyelitis (1%). In addition to infections caused by encapsulated bacteria, opportunistic infections were relatively common and were caused by P. carinii, members of the herpes virus family (including cytomegalovirus), Cryptosporidium, Cryptococcus, Candida, Histoplasma, and Bartonella. Sclerosing cholangitis occurred in 5 patients and in 4 of these was associated with Cryptosporidium infection. Eight patients had died at the time of their entry into the Registry; 2 of pneumonia (1 P. carinii and 1 cytomegalovirus), 2 of encephalitis (1 ECHO virus and 1 cytomegalovirus), 2 of malignancy (both hepatocellular carcinoma), 1 of sclerosing cholangitis caused by Cryptosporidium, and 1 of hemolytic uremic syndrome.
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PMID:The X-linked hyper-IgM syndrome: clinical and immunologic features of 79 patients. 1466 87

X-linked hypohidrotic ectodermal dysplasia (XHED), an inherited disease recognized in humans, mice, and cattle, is characterized by hypotrichosis, a reduced number or absence of sweat glands, and missing or malformed teeth. In a subset of affected individuals and animals, mutations in the EDA gene (formerly EDI), coding for ectodysplasin, have been found to cause this phenotype. Ectodysplasin is a homotrimeric transmembrane protein with an extracellular TNF-like domain, which has been shown to be involved in the morphogenesis of hair follicles and tooth buds during fetal development. Some human XHED patients also have concurrent immunodeficiency, due to mutations in the NF-kappaB essential modulator protein (IKBKG; formerly NEMO), which is also encoded on the X chromosome. In a breeding colony of dogs with XHED, immune system defects had been suspected because of frequent pulmonary infections and unexpected deaths resulting from pneumonia. To determine if defects in EDA or IKBKG cause XHED in the dogs, linkage analysis and sequencing experiments were performed. A polymorphic marker near the canine EDA gene showed significant linkage to XHED. The canine EDA gene was sequenced and a nucleotide substitution (G to A) in the splice acceptor site of intron 8 was detected in affected dogs. In the presence of the A residue, a cryptic acceptor site within exon 9 is used, leading to a frame shift and use of a premature stop codon that truncates the translation of both isoforms, EDA-A1 and EDA-A2, resulting in the absence of the TNF-like homology domain, the receptor-binding site of ectodysplasin.
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PMID:Mutation identification in a canine model of X-linked ectodermal dysplasia. 1615 97

X-linked alpha thalassemia mental retardation (ATR-X) syndrome is associated with profound developmental delay, facial dysmorphism, genital abnormalities, and alpha thalassemia. Patients with ATR-X syndrome frequently present with gastrointestinal problems, in particular feeding difficulties, regurgitation and vomiting, abdominal pain, distension, and chronic constipation. Parental reports of prolonged food refusal and distress in these children are common and although these episodes are suspected to be gastro-intestinal in origin they are rarely investigated. Death in early childhood from aspiration of vomitus or from pneumonia presumed to be secondary to aspiration has been recorded in a number of ATR-X cases. In this report we review the gastrointestinal phenotype of ATR-X syndrome in 128 cases. We also demonstrate that in two siblings, regurgitation was secondary to gastric pseudo-volvulus, a condition in which the stomach does not have a normal system of peritoneal ligaments and changes position with possible torsion around itself. Furthermore, ultra-short Hirschsprung disease with colonic hypoganglionosis was shown and this may contribute to the severe constipation affecting these children.
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PMID:Gastrointestinal phenotype of ATR-X syndrome. 1668 41

The X-linked McLeod neuroacanthocytosis syndrome (MLS) has originally been denoted as 'benign' McLeod myopathy. We assessed the clinical findings and the muscle pathology in the eponymous index patient, Hugh McLeod, and in nine additional MLS patients. Only one patient had manifested with neuromuscular symptoms. During a mean follow-up of 15 years, however, eight patients including the initial index patient showed elevated skeletal muscle creatine kinase levels ranging from 300 to 3000 U/L, and had developed muscle weakness and atrophy. Two patients had disabling leg weakness. Muscle histology was abnormal in all 10 patients. Clear but unspecific myopathic changes were found in only four patients. All patients, however, had neurogenic changes of variable degree. Post-mortem motor and sensory nerve examinations support the view that muscle atrophy and weakness are predominantly due to an axonal motor neuropathy rather than to a primary myopathy. Multisystem manifestations developed in eight patients at a mean age of 39 years. Three patients manifested with psychiatric features comprising schizophrenia-like psychosis and personality disorder, two presented with generalized seizures and one with chorea. During follow-up, seven patients developed chorea, six had psychiatric disorders, five had cognitive decline and three had generalized seizures. Five patients died because of MLS-related complications including sudden cardiac death, chronic heart failure and pneumonia between 55 and 69 years. In conclusion, our findings confirm that MLS is not a benign condition but rather a progressive multisystem disorder sharing many features with Huntington's disease.
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PMID:McLeod myopathy revisited: more neurogenic and less benign. 1805 95

There are no epidemiological studies from the British Isles of chronic granulomatous disease, characterized by recurrent, life-threatening bacterial and fungal infections and inflammatory sequelae. Patients were enrolled in a national registry and medical records were analysed. Of 94 subjects, 69 had X-linked disease, 16 had autosomal recessive disease and nine were unknown. Prevalence was 7.5/million for 1990-99 and 8.5/million for 1980-89. Suppurative adenitis, abscesses and pneumonia presented commonly. Twenty-three of 30 patients who underwent high resolution computerized tomography had chronic respiratory disease. Inflammatory sequelae included bowel stricture and urogenital tract granulomata. Growth failure was common; 75% of those measured were below the population mean. All patients received prophylactic antibiotics and 93% anti-fungal prophylaxis. Interferon gamma was used to treat infection, but rarely as prophylaxis. Despite prophylaxis, estimated survival was 88% at 10 years but 55% at age 30 years. Morbidity remains significant, severe infectious complications common. Curative treatments including stem cell transplantation should be considered for patients with frequent or serious complications.
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PMID:Special article: chronic granulomatous disease in the United Kingdom and Ireland: a comprehensive national patient-based registry. 1841 Jun 35

Chronic granulomatous disease (CGD) is characterized by defects in the superoxide producing enzyme NADPH oxidase causing phagocytes to improperly clear invading pathogens. Here we report findings of a late presenting 16-year-old female with X-linked CGD. The patient presented with community-acquired pneumonia, but symptoms persisted for 2 weeks during triple antimicrobial coverage. Cultures revealed Aspergillus fumigatus which was resolved through aggressive voriconazole treatment. Neutrophil studies revealed NADPH oxidase activity and flavocytochrome b(558) levels that were 4-8% of controls and suggested carrier status of the mother. We found a null mutation in the CYBB gene (c.252insAG) predicting an aberrant gp91(phox) protein (p.Cys85fsX23) in the heterozygous state. Methylation analysis demonstrated extremely skewed X chromosome inactivation favoring the maternally inherited defective gene. In conclusion, a novel mutation in the CYBB gene and an extremely skewed X-inactivation event resulted in the rare expression of the CGD phenotype in a carrier female.
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PMID:X-linked chronic granulomatous disease secondary to skewed X chromosome inactivation in a female with a novel CYBB mutation and late presentation. 1900 69

X-linked lissencephaly with abnormal genitalia (XLAG) is characterized by lissencephaly, absent corpus callosum and ambiguous genitalia. We examined hypothalamic dysfunctions in a XLAG case with a novel mutation of the ARX gene, and performed immunohistochemical evaluation of the diencephalons in autopsy brain. A 1-year-old boy showed intractable epilepsy, persistent diarrhea and disturbed temperature regulation. This case had abnormalities in circadian rhythms and pituitary hormone reserve test. He died of pneumonia. The globus pallidus and subthalamic nucleus was not identified, and the putamen and thalamus were dysplasic. The suprachiasmatic nucleus was absent. A few neurons immunoreactive for vasopressin seemed to form the ectopic supraoptic-like nucleus. The diencephalons were disturbed differently in each sub-region, and the changes may be related to various hypothalamic dysfunctions.
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PMID:Analysis of the hypothalamus in a case of X-linked lissencephaly with abnormal genitalia (XLAG). 1884 66

CGD is an immunodeficiency caused by deletions or mutations in genes that encode subunits of the leukocyte NADPH oxidase complex. Normally, assembly of the NADPH oxidase complex in phagosomes of certain phagocytic cells leads to a "respiratory burst", essential for the clearance of phagocytosed micro-organisms. CGD patients lack this mechanism, which leads to life-threatening infections and granuloma formation. However, a clear picture of the clinical course of CGD is hampered by its low prevalence (approximately 1:250,000). Therefore, extensive clinical data from 429 European patients were collected and analyzed. Of these patients 351 were males and 78 were females. X-linked (XL) CGD (gp91(phox) deficient) accounted for 67% of the cases, autosomal recessive (AR) inheritance for 33%. AR-CGD was diagnosed later in life, and the mean survival time was significantly better in AR patients (49.6 years) than in XL CGD (37.8 years), suggesting a milder disease course in AR patients. The disease manifested itself most frequently in the lungs (66% of patients), skin (53%), lymph nodes (50%), gastrointestinal tract (48%) and liver (32%). The most frequently cultured micro-organisms per episode were Staphylococcus aureus (30%), Aspergillus spp. (26%), and Salmonella spp. (16%). Surprisingly, Pseudomonas spp. (2%) and Burkholderia cepacia (<1%) were found only sporadically. Lesions induced by inoculation with BCG occurred in 8% of the patients. Only 71% of the patients received antibiotic maintenance therapy, and 53% antifungal prophylaxis. 33% were treated with gamma-interferon. 24 patients (6%) had received a stem cell transplantation. The most prominent reason of death was pneumonia and pulmonary abscess (18/84 cases), septicemia (16/84) and brain abscess (4/84). These data provide further insight in the clinical course of CGD in Europe and hopefully can help to increase awareness and optimize the treatment of these patients.
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PMID:Chronic granulomatous disease: the European experience. 1938 1

Chronic granulomatous disease (CGD) is a rare inherited immunodeficiency disorder. The clinical presentation is varied depending on the degree of involvement of the NADPH oxidase system responsible for the oxidative burst of neutrophils. We present 3 cases of variant X-linked CGD in an effort to introduce the disease and highlight the importance and limitations of CGD screening. The variant X-linked form of CGD results in a less severe phenotype and frequently presents later in life. Variant X-linked CGD is difficult to diagnose, but is becoming more readily recognized based on improved testing methods. A high index of suspicion in the setting of unusual infections such as Burkholderia cepacia pneumonia is essential to make the diagnosis. Family screening can lead to early intervention, prophylaxis, and appropriate genetic counseling.
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PMID:Family clusters of variant X-linked chronic granulomatous disease. 2011 50


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