Extended molecular spectrum of beta- and alpha-thalassemia in Oman.

Sickle cell disease is known to be very common in the Omani population, although data are limited concerning beta-thalassemia (beta-thal). We report the molecular background of 87 unrelated patients from the Sultanate of Oman, diagnosed with beta-thal major (beta-TM), beta-thal intermedia (beta-TI) or minor. Diagnosis was based on clinical and hematological data and confirmed by molecular analysis. We found 11 different beta-thal determinants in our cohort, which consists of subjects from different regions of Oman. Six of these mutations have not been previously reported in the Omani population. The prevalence of alpha-thal single gene deletions (-alpha(3.7) and -alpha(4.2)) in the same cohort was very high (58.3%). These data will contribute to the implementation of a country-wide service for early molecular detection of hemoglobinopathies and for providing genetic counseling following premarital screening.