Saturday, July 20, 2019

Acatalasia :: essays research papers

Acatalasia Several rare electrophoretic variants of red cell catalase were identified by Baur (1963). Nance et al. (1968) also described electrophoretic variants. Data on gene frequencies of allelic variants were tabulated by Roychoudhury and Nei (1988). Wieacker et al. (1980) assigned a gene for catalase to 11p by study of man-mouse cell hybrid clones. In the hybrid cells, detection of human catalase was precluded by the complexity of the electrophoretic patterns resulting from interference by a catalase-modifying enzyme activity. Therefore, a specific antihuman antibody was used in conjunction with electrophoresis. In mouse, catalase is not syntenic to the beta-globin cluster or to LDH-A. Junien et al. (1980) investigated catalase gene dosage effects in a case of 11p13 deletion, a case of trisomy of all of 11p except 11p13, and a case of trisomy 11p13. The results were consistent with assignment of the catalase locus to 11p13 and its linkage with the WAGR complex (194070). Assay of catalase activity should be useful in identifying those cases of presumed new mutation aniridia that have a risk of Wilms tumor or gonadoblastoma, even in the absence of visible chromosomal deletion. In karyotypically normal patients with aniridia, Wilms tumor, or the combination of the two, Ferrell and Riccardi (1981) found normal catalase levels. Niikawa et al. (1982) confirmed the close linkage of catalase to the gene of the WAGR complex by demonstrating low levels of catalase activity in the erythrocytes of 2 unrelated patients with the WAGR syndrome and small deletions in 11p. From the study of dosage in 2 unrelated patients with an interstitial deletion involving 11p13, Narahara et al. (1984) concluded that both the catalase locus and the WAGR locus are situated in the chromosome segment 11p1306-p1305, with catalase distal to WAGR. Boyd et al. (1986) described a catalase RFLP with 2 different enzymes and used these polymorphisms to exclude deletion of the catalase gene in patients with sporadic aniridia, including one who was known to have a deletion and another suspected of having a deletion. Mannens et al. (1987) found deletion of the catalase locus in 6 of 9 patients with aniridia (AN2; 106210). One of these catalase-defic ient aniridia patients had a normal karyotype. No catalase deletion could be demonstrated in 7 Wilms tumors. By classic linkage studies using RFLPs of the several genes as markers, Kittur et al. (1985) derived the following sequence of loci: cen-CAT--16 cM-CALC--8 cM-PTH-pter, with the interval between CAT and PTH estimated at 26 cM.

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