OBJECTIVETo explore the clinical significance of genetic detection and changes of red cell enzyme activities of pyrimidine 5' nucleotidase (P5'N), pyruvate kinase (PK) and glucose-6-phosphate dehydrogenase (G-6-PD) in patients with α-thalassaemia (α-thal).

METHODSThree α-thal patients were further processed to gene detection by PCR-trans-dot blot and gap-PCR, and red cell enzymes activities by absorbance at 260 and 280 nm (A) for P5'N and fluorescence spot test for PK and G-6-PD.

RESULTSRed cells in 3 α-thal cases were microcytic hypochromic with obvious augmented target cells and basophilic stippling erythrocytes. Two patients had anemia, splenomegaly, hyperbilirubinemia and augmented LDH. HbH was positively identified by hemoglobin electrophoresis and hemoglobin cellulose acetate membrane electrophoresis; the other patient had no such abnormalities. Genotypes of 3 patients were of (-α(3.7)/--(SEA)), (αα(QS)/--(SEA))and (--(SEA)), respectively. The activity of P5'N (but not for PK and G-6-PD) in red cell reduced.

CONCLUSIONSThis is the first documented α-thal with P5'N deficiency. Genetic detection might be clinical significant for the diagnosis and pedigree screening of α-thal.