Alpha thalassaemia in Zambian newborn.

The umbilical cord blood from 109 consecutive Zambian neonates (excluding those found to be anti-HIV positive) were analysed for haemoglobin (Hb) Bart's and for alpha thalassaemia by restriction endonuclease analysis. This showed that 52.3% had the genotype alpha alpha/alpha alpha, 38.5% had -alpha 3.7/alpha alpha, 7.3% had -alpha 3.7/-alpha 3.7 and 1.8% had alpha alpha alpha/alpha alpha. The alpha thalassaemia gene (-alpha) frequency was 0.27. There were no apparent differences in gene frequency between six major Zambian ethnic groups. Detection of Hb Bart's identified all alpha-thalassaemia homozygotes (-alpha/-alpha), but fewer than 10% of heterozygotes (-alpha/alpha alpha). alpha-thalassaemia was associated with slight but significant anaemia and microcytosis.