β-thalassemia is a group of heterogeneous recessive
disorders common in many parts of the world. Al-Qatif and Al-Hassa
oases in the Eastern Province of Saudi Arabia are regions known
for high frequency of these disorders. Using two molecular
methods, based on multiplexing-amplification refractory system and
reverse hybridization principles, the spectrum of β-thalassemia in the region was studied. Sixty-nine subjects with known
β-thalassemia disease and volunteers with high hemoglobin
A2(HbA2) and low mean corpuscular volume (MCV) were included in this study.
Ten mutations were detected in 91% of the subjects under study. Six of these
mutations had previously been observed while the other four mutations are reported
here for the first time. In addition, four of the mutations accounted for 76.8% of the subjects studied. IVSII-1 (G > A), IVSI-5 (G > A), and codon 39 (C > T) mutations were found to be the most frequent. However, the
frequencies of different mutations reported here are slightly
different from those reported earlier. A number of these mutations
were also found in the neighboring countries, which can be
explained in terms of gene flow.
