A frequent TG deletion near the polyadenilation site of the human HEXB gene. Occurrence of an irregular DNA structure and a conserved nucleotide sequence motif in the 3'untranslated region.

KLEIMAN F.E,; OLLER A.,; AKERMAN B,; KREMER R,; GRAVEL,; ARGARAÑA CE

WILEY-LISS, DIV JOHN WILEY & SONS INC

Año: 1998 vol. 12 p. 320 - 320

hile screening for new mutations in the HEXB gene, which encodes the beta-subunit of beta-hexosaminidase, a TG deletion (deltaTG) was found in the 3´ untranslated region (3´UTR) of the gene, 7 bp upstream from the polyadenylation signal. Examination of DNA samples of 145 unrelated Argentinean individuals from different racial backgrounds showed that the deltaTG allele was present with a frequency of approximately 0.1, compared with the wild-type (WT) allele. The deletion was not associated with infantile or variant forms of Sandhoff disease when present in combination with a deleterious allele. Total Hex and Hex B enzymatic activities measured in individuals heterozygous for deltaTG and a null allele, IVS-2 + 1G-->A (G-->A), were approximately 30% lower than the activities of G-->A/WT individuals. Analysis of the HEXB mRNA from leukocytes of deltaTG/WT individuals by RT-PCR of the 3´UTR showed that the deltaTG allele is present at lower level than the WT allele. By polyacrylamide gel