[Thalassemic alleles in Mexican mestizos]

We present an analysis of the thalassemic alleles observed in Mexican mestizos. In 18 unrelated patients with mild to severe hemolytic anemia we saw 16 with beta-thal and two with alpha-thal and identified 25 chromosomes with 14 different alleles (10 for beta-thal), predominating the Mediterranean type (seven beta-thal and two alpha-thal). The most common mutation was the nonsense Cd 39 observed in seven chromosomes (28%); the other mutants were three Asian alleles, one beta-thal Indian (IVS-1 nt 5 G-->C), two Southeast Asian alpha-thal (-SEA and the -FIL), one Kurdish Jew (-28 A-->C) and one Mexican (Cd 11 -T). These findings suggest a marked molecular heterogeneity in the thalassemia genes in Mexico.