A new polymorphism (G -> A) in the psi zeta 1 globin gene

Background and Objectives. alpha-globin cluster polymorphisms are obtained with specific restriction enzymes (Xba I, Eco RI, Sac I, Apa I, Bgl II, etc ) that can also have implications for genetic analysis. Design and Methods. We studied three unrelated patients; one from Argentina, one from Spain and one from Australia but of Polish origin. Genomic DNA was digested with several different restriction enzymes and probes, amplified and seque nced with an ABI Prism 310 sequencer. Results. Three patients had an abnormal 26 hb band when their DNA was studi ed with restriction enzyme : Bgl II and zeta probe. A fragment of 944 bp wa s amplified with primers that cover from -280 to +714 bp of the recognition sequence of Bgl II enzyme (AGATCT) localized 5' from pseudogene zeta 1. Af ter digestion of this PCR product with Bgl II, two fragments of 714 and 280 bp were produced in normal controls, whereas in patient #1 the PCR fragmen t was undigested and in patients #2 and #3 both undigested and digested fra gments were observed. Sequencing of the PCR fragment showed that in all thr ee patients it was the same polymorphism (G-->A) at nucleotide 153171 of th e 16 p sequence found in the Bgl II recognition site that changed to AAATCT . Interpretation and Conclusions. We describe a new polymorphism in the psi z eta 1 first exon Bgl II restriction site (G-->A). The polymorphism is assoc iated in cis with haplotype -alpha 3.7. The fragment obtained by PCR enable d us to corroborate the presence of the polymorphism quickly without having to use complicated sequencing techniques. (C) 2000, Ferrata Storti Fondati on.