Distinctive features of polycythaemia vera in New Zealand Polynesians.

AIM: The aim of this study was to examine a potential ethnic disparity in the phenotype of polycythaemia vera (PV) between New Zealand European and Polynesian patients. METHOD: A retrospective review of medical records was conducted at Middlemore Hospital to identify adult patients with PV diagnosed between 1987 and 2007. Data extracted included diagnostic criteria, ethnicity, age, complications and survival. RESULTS: Eighty-eight adult patients with PV were identified during 1987-2007, 49 (55.7%) were Europeans and 36 (40.9%) Polynesians. The most striking finding was that Polynesian patients presented almost 14 years younger than Europeans (mean age of 54 years versus [vs] 68, respectively; P<.001). The white cell and platelet counts were higher in Polynesians compared with Europeans (mean white cell count of 22x109/L vs 13x109/L; mean platelet count of 648x109/L vs 512x109/L, respectively; P<.05 for both). The rate of JAK2 V617F mutation in Polynesians was 96%, equivalent to other large cohorts of European patients. The rates of long-term complications were comparable between Polynesians and Europeans, but the predicted impact on life expectancy was more severe for Polynesians. CONCLUSION: New Zealand Polynesian patients present with a distinctive PV phenotype. Their younger age at presentation suggests a different risk factor profile or a higher genetic susceptibility. We hope our observations initiate larger epidemiological and genetic studies to help elucidate the cause.

Maternal and perinatal predictors of newborn iron status.

AIM: To describe iron status at birth in a population sample of children. METHOD: Cord blood samples were obtained at birth from 131 infants enrolled in the cohort study Growing Up in New Zealand. Cord blood serum ferritin (SF) and haemoglobin (Hb) concentrations were measured and associations of SF and Hb with maternal and birth characteristics were determined. RESULTS: Demographics were comparable to the larger cohort, except for having a higher pre-pregnancy body mass index (26.9 vs. 25.4 kg/m2, P=0.005), lower frequency of cigarette smoking during pregnancy (2% vs. 11%, P=0.0004), and smaller proportion with birth-weight <2500 g (0% vs. 5%, P=0.03). Median (interquartile range) SF was 135 (88-180) mcg/L and mean (plus or minus SD) Hb was 160 plus or minus 17 g/L. Eight newborns (7%) had cord SF levels indicative of iron deficiency (SF <35 mcg/L), two newborns were anaemic (Hb <130 g/L) and none had iron deficiency anaemia. Median SF was lower in newborns whose mothers consumed greater than or equal to 3 servings of milk/day during the pregnancy (131 vs. 151 mcg/L, P=0.04). No other associations with SF or Hb were observed. CONCLUSION: Iron deficiency is present in 7% of newborns in New Zealand. Newborns whose mothers consumed more milk during pregnancy had a lower median SF concentration.

Novel sequence insertion in a Mâori patient with transfusion-dependent beta-thalassaemia.

Although beta-thalassaemia is common throughout the world, it has not been previously described in Polynesia. We report a novel sequence insertion where homozygosity for the defect results in transfusion-dependent anaemia. The repeated 45 base pair (bp) insertion causes duplication of the start codon and consequent transcription from the original initiation code would be predicted to lead to the production of an irrelevant seven-residue peptide, while residual translation from the novel initiation site would result in diminished yields of beta-globin and consequent clinical beta(+)-thalassaemia.