SOD-A and chromosome 21

Abstract

A balanced maternal chromosome translocation (9p24;21q214) resulted in two offspring with unbalanced karyotypes. One of these, a girl trisomic for both segment 9pter to 9p24 and segment 21pter to 21q214, was found to have a SOD-A activity not significantly different from those found in a group of five cases with trisomy 21. However, clinical evaluation of this girl revealed no symptoms of the Down syndrome. These findings suggest that, providing the gene dosage theory is correct, the gene for SOD-A is probably localized on chromosome 21 proximal to, or in, band q21.

Superoxide Anion Radical (O·̄2), Superoxide Dismutases, and Related Matters

“…However, this seems unlikely. Thus a partial trisomy 21 with overdosages of Cu,Zn-SOD was associated with none of the usual symptoms (58). This lack of correlation of symptoms with overdosage has been replicated (59).…”

Red cell superoxide dismutase, glutathione peroxidase and catalase in down syndrome patients with and without manifestations of Alzheimer disease

“…This finding has permitted the localization of the region responsible for the syndrome to segment 21q22 [for review, see Park et al, 19871. The finding of normal SOD-1 activity in some translocation DS patients has been interpreted to mean that the SOD-1 gene does not play a role in the DS phenotype [Leschot et al, 1981;Matthei et al, 1981;Habedank and Rodewald, 19821. Our finding that older DS patients with AD have red cell SOD-1 activities within the normal range for matched controls, indicates that interpretation of red cell SOD activity must always be made relative to matched controls. The recent report of Jeziorowski et al [1988], which describes several children with typical trisomy 21 and normal SOD-1 activity, supports our conclusion that under the conditions used in this study, red cell SOD activity will not always reflect the SOD-1 gene dosage.…”

Atypical Down syndrome and partial trisomy 21

“…Although the locus for SOD-1 appears to be in band 21q22 (Sinet et al 1976, Yamamoto et al 1979, Leschot et al 1981, Habedank & Rodewald 1982, its gene dosage has been quantitated to indicate the presence or activity (Poisonnier et al 1976, Couturier et al 1979, Taysi et al 1982) of trisomy 21 material that is separate and or proximal to that responsible for the DS phenotype (Mattei et al 1981, Leschot et al 1981, Habedank & Rodewald 1982. It has also been amply shown that trisomy for the distal segment of 21q, whether it be more or less than 21q22, is responsible for the DS phenotype.…”

“…Sinet et al (1976) has mapped soluble superoxide dismutase (SOD) to the long arm of chromosome 21. Its precise sublocalization appears to be in band 21q22 (Yamamoto et al 1979, Leschot et al 1981, Habedank & Rodewald 1982. SOD has been found to show a gene dosage effect of increased activity by 150% in nucleated trisomy 21 cells (Feaster et al 1977, Francke 1981 as well as increased quantity as shown by 2-D gel electrophoresis (Brown et al 1981).…”