Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q00604 (X-linked)
 16,883 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Some boys with X-linked chronic granulomatous disease (CGD) have red cells of the rare McLeod phenotype in the Kell blood group system. Only one example of this phenotype has previously been described in a non-CGD subject. We have studied a 10-year-old boy and a maternal brother who do not have CGD and whose red cells are of the McLeod type . The boy presented as a haematological problem with red-cell abnormalities. These were acanthocytosis, anisocytosis and 'tailing' in the osmotic fragility curve, changes now known to occur with the McLeod phenotype. Subsequent studies revealed his rare blood group. A family study has established that an uncle also has acanthocytic red cells and the McLeod phenotype. In addition the boy's sister, mother and maternal grandmother all show red-cell mosaicism with double populations of McLeod acanthocytes and normal red cells of common Kell type. The gene that determines inheritance of the McLeod phenotype is X-linked and the mosaicism present in female carriers is believed to result from X chromosome inactivation by the Lyon effect. The study provides further evidence that the McLeod phenotype arises by inheritance of a variant X-linked modifying gene and not through inheritance of a variant gene at the Kell autosomal locus. It also represents the first occasion that a person of rare blood group has been recognized because of an associated anomaly in red cell morphology.
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PMID:Hereditary acanthocytosis associated with the McLeod phenotype of the Kell blood group system. 47 9

The Kell blood group has 18 associated red cell antigens. One, named KX, is the product of an X-linked gene and appears to be a precursor in the Kell biosynthetic pathway. Lack of KX on red cells, caused by inheritance of a variant allele at the X-linked locus, results in gross changes in Kell antigenicity, an effect called the McLeod phenotype. Such cells also show striking morphologic changes. Normal phagocytic leukocytes lack Kell antigens but have strong KX. The leukocytes of boys with X-linked chronic granulomatous disease lack KX antigen and have defective bactericidal function. The fundamental defect in chronic granulomatous disease appears to be failure to inherit the X-linked gene that determines KX synthesis. The enzymatic and functional disorders of the leukocytes, and the structural changes in the red cells, are consequences that follow.
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PMID:The Kell blood group, Kx antigen, and chronic granulomatous disease. 83 61

A young man with X-linked chronic granulomatous disease of childhood, who is of the rare McLeod phenotype with antibodies in his serum shown to be hemolytic and reactive against all red cells with normal expressions of the Kell antigens, developed a severe Nocardia pneumonia with abscess formation and was subsequently treated successfully with granulocyte transfusions in spite of the presence of anti-KX in the patient's serum. The anti-KX did not appear to alter significantly the effectiveness of the transfused granulocytes; it did, however, cause a mild hemolytic transfusion reaction. The patient made a remarkable recovery from this episode and his condition has progressed to a state satisfactory enough for him to donate his own blood for storage and possible use in the future.
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PMID:Chronic granulomatous disease and the Mcleod phenotype. Successful treatment of infection with granulocyte transfusions resulting in subsequent hemolytic transfusion reaction. 83 62

The McLeod phenotype is inherited as an X-linked characteristic. The red cells have weak antigenicity in the Kell blood group and lack Kx, a precursor-like substance that appears to be necessary for proper biosynthesis of Kell antigens. Kx antigen is also required for establishment of normal cell morphology. Absence of Kx antigen causes a membrane abnormality, in which the most prominent feature is acanthocytosis, and a compensated haemolytic state. The X-linked gene that determines normal Kx production is called X1k. Inheritance of a variant allele at the Xk locus is responsible for lack of Kx synthesis and the McLeod phenotype. The Xk locus is inactivated by the Lyon effect, and female carriers of the variant gene exhibit blood group mosaicism in the Kell system and have a dual red cell population of acanthocytes and discocytes.
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PMID:Haematological changes associated with the McLeod phenotype of the Kell blood group system. 87 35

Leukocytes of nine unrelated boys with X-linked chronic granulomatous disease lack Kx antigen. In three of these cases, the red cells also lack Kx and have the McLeod phenotype and abnormal morphology. X-linked chronic granulomatous disease CGD can thus be separated into two types. Type I cases have an antigenic deficiency that is restricted to the phagocytic leukocytes while in type II, the deficiency involves both leukocytes and red cells. Red cells of type II CGD patients have enhanced i antigen activity suggesting that they are under hemopoietic stress. Normal Kx synthesis is directed by an X-linked gene named X1k. Three variants, X2k, X3k, and X4k order the different permutations of leukocyte and red cell Kx antigen production that have been recognized.
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PMID:Kx antigen, the McLeod phenotype, and chronic granulomatous disease: further studies. 100 58

Fifteen antigenic determinants are known to be related to the Kell blood group. Some boys with X-linked chronic granulomatous disease have the very rare McLeod or Ko phenotype on their red cells. Serological studies of the McLeod type suggest that the weak Kell antigens that are present differ qualitatively and quantitatively from those on red cells of common Kell type. A new antigen, Kx, has been characterized and shown to be present on red cells and neutrophil leucocytes. Lack of red-cell Kx is associated with the McLeod phenotype, lack of leucocyte Kx is associated with chronic granulomatous disease.
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PMID:Chronic granulomatous disease and the Kell blood groups. 119 46

A genetic locus (RP3) for X-linked retinitis pigmentosa (XLRP) has been assigned to Xp21 by genetic linkage studies and has been supported by two Xp21 male deletion patients with XLRP. RP3 appears to be the most centromeric of several positioned loci, including chronic granulomatous disease (CGD), McLeod phenotype (XK), and Duchenne muscular dystrophy (DMD). In one patient, BB, the X-chromosome deletion includes RP3 and extends to within the DMD locus. Using a DMD cDNA, the centromeric endpoint of this patient was cloned and used as a starting point for chromosome walking along a normal X chromosome. A single-copy probe, XH1.4, positioned near the centromeric junction but deleted in BB, was used along with a CGD cDNA probe to establish a refined long-range physical map. Both probes recognized a common SfiI fragment of 205 kb. As the CGD gene covers approximately 30-60 kb, the RP3 locus has been restricted to approximately 150-170 kb. A CpG island, potentially marking a new gene, was identified within the SfiI fragment at a position approximately 35 kb from the deletion endpoint in BB.
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PMID:Physical mapping at a potential X-linked retinitis pigmentosa locus (RP3) by pulsed-field gel electrophoresis. 176 46

Nineteen cases are described, including 12 cases from three different families and 7 nonfamilial cases, in which multisystem neurological disease was associated with acanthocytosis in peripheral blood and normal plasma lipoproteins. Mild acanthocytosis can easily be overlooked, and scanning electron microscopy may be helpful. Some neurologically asymptomatic relatives with significant acanthocytosis were identified during family screening, including some who were clinically affected. The mean age of onset was 32 (range 8-62) yrs and the clinical course was usually progressive but there was marked phenotypic variation. Cognitive impairment, psychiatric features and organic personality change occurred in over half the cases, and more than one-third had seizures. Orofaciolingual involuntary movements and pseudobulbar disturbance commonly caused dysphagia and dysarthria that was sometimes severe, but biting of the lips or tongue was rarely seen. Chorea was seen in almost all symptomatic cases but dystonia, tics, involuntary vocalizations and akinetic-rigid features also occurred. Two cases had no movement disorder at all. Computerized tomography often demonstrated cerebral atrophy. Caudate atrophy was seen less commonly, and nonspecific focal and symmetric signal abnormalities from the caudate or lentiform nuclei were seen by magnetic resonance imaging in 3 out of 4 cases. Depression or absence of tendon reflexes was noted in 13 cases and neurophysiological abnormalities often indicated an axonal neuropathy. Sural nerve biopsies from 3 cases showed evidence of a chronic axonal neuropathy with prominent regenerative activity, predominantly affecting the large diameter myelinated fibres. Serum creatine kinase activity was increased in 11 cases but without clinical evidence of a myopathy. Postmortem neuropathological examination in 1 case revealed extensive neuronal loss and gliosis affecting the corpus striatum, pallidum, and the substantia nigra, especially the pars reticulata. The cerebral cortex appeared spared and the spinal cord showed no evidence of anterior horn cell loss. Two examples of the McLeod phenotype, an X-linked abnormality of expression of Kell blood group antigens, were identified in a single family and included 1 female. The genetics of neuroacanthocytosis are unclear and probably heterogeneous, but the available pedigree data and the association with the McLeod phenotype suggest that there may be a locus for this disorder on the short arm of the X chromosome.
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PMID:Neuroacanthocytosis. A clinical, haematological and pathological study of 19 cases. 199 79

Chronic granulomatous disease (CGD) is a genetic syndrome, mostly inherited as an X-linked recessive trait, characterized by severe and recurrent infections due to defective neutrophil leukocytes and monocytes respiratory burst and microbicidal activity. Consequently, the affected patients are prone to infections by catalase-positive bacteria and fungi. The Authors describe a case of X-linked CGD with red cells of the rare McLeod phenotype. These red cells show acanthocytosis and are not reacting with anti-Kx antibody. Moreover, the Authors discussed the diagnosis and chemotherapy of CGD in addition to biochemical and clinical characterization of McLeod phenotype.
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PMID:[Chronic granulomatous disease and McLeod phenotype. Description of a case]. 237 52

In a patient suffering from X-linked chronic granulomatous disease (X-CGD)--a disorder of phagocytesuperoxide generation--and McLeod syndrome, characterized by the absence of the red cell Kell antigen, we identified a deletion of the entire X-CGD gene by means of DNA hybridization with a cDNA probe. Our findings suggest that the X-CGD and McLeod loci are physically close in the p21 region of the X chromosome proximal to the Duchenne muscular dystrophy locus.
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PMID:Gene deletion in a patient with chronic granulomatous disease and McLeod syndrome: fine mapping of the Xk gene locus. 333 97


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