A +8 (-->CT) mutation within the 5' untranslated region of beta-globin down-regulates the mRNA transcription.

The 5' untranslated region (5'UTR) of beta-globin has been well characterized and is often used as a model for eukaryotic transcription/translation, but there are still questions regarding the mechanism of translational control. Mutations affecting the Cap site at + 1 and at positions +10, +22, +33 and +40-43 have been described, and it is thought that the initiator element required for transcription stretches from -2 to +7 relative to the Cap site with a downstream element situated from +10 to +15. The influence on initiation or translation of sequences between +7 and +10 is unknown. We report here a family with beta-thalassemia (beta-thal) who have a + 8 (CT) mutation. Molecular studies indicate that this mutation leads to a reduction in mRNA levels and we discuss the implications of a CT change at this position on the transcription/translation process.