Related Experiment Videos
alpha-thalassemia in the United Arab Emirates
1Department of Pediatrics and Genetics and Department of Health and Medical Services, Dubai, United Arab Emirates.
Insights
Neonatal screening in the UAE reveals a high prevalence of alpha-thalassemia (alpha-thal), with nearly half of newborns having an alpha-globin gene defect. This study highlights significant genetic diversity and a high incidence of alpha-thalassemia in the region.
Area of Science:
- Genetics
- Hematology
- Public Health
Background:
- Alpha-thalassemia (alpha-thal) is a common inherited blood disorder.
- Understanding the prevalence and genetic basis of alpha-thal in the United Arab Emirates (UAE) is crucial for public health initiatives.
Purpose of the Study:
- To conduct a neonatal screening survey for alpha-thalassemia in UAE nationals.
- To identify the spectrum of alpha-thal mutations and their frequencies.
- To correlate genotypes with phenotypes in patients with Hb H disease or Hb H-like syndrome.
Main Methods:
- Neonatal screening of 418 consecutive cord blood samples from UAE nationals.
- Molecular analysis to detect alpha-globin gene defects and specific alpha-thal mutations.
- Genotype-phenotype correlation in 22 patients with Hb H disease or Hb H-like syndrome.
Main Results:
- Nearly half (49%) of the screened neonates exhibited an alpha-globin gene defect.
- Common deletional mutations (-alpha3.7 and -alpha4.2) and four non-deletional mutations (alphaPA-1, alphaPA-2, Hb CS, alpha-5nt del) were identified.
- Genotype-phenotype analysis showed a generally mild to moderate presentation of Hb H disease in the UAE population.
Conclusions:
- The UAE has a high incidence of alpha-thalassemia, with considerable genetic heterogeneity.
- The identified mutations and their frequencies provide valuable data for genetic counseling and management.
- Clinical manifestations of Hb H disease in the UAE appear to be generally mild to moderate.
Abstract:
A neonatal screening survey of alpha-thalassemia (alpha-thal) among the United Arab Emirates (UAE) nationals was conducted on 418 consecutive cord blood samples. Our findings demonstrate that 49% of the cases studied were found with an alpha-globin gene defect. The gene frequency of the -alpha3.7 was 0.2847 and that of the -alpha4.2 was 0.0072. Four nondeletional alpha-thal mutations were found; alphaPA-1, alphaPA-2, Hb CS and alpha-5nt del with gene frequencies of 0.0036, 0.0012, 0.0024, and 0.0072, respectively. We also report here the genotype-phenotype correlation in 22 patients with Hb H disease or Hb H-like syndrome. Of these, 6 were homozygous for the alphaPA-1 mutation, 2 were homozygous for Hb CS, and 14 were compound heterozygous for either alphaPA-1, Hb CS, alpha-5nt del or --MED-I, with the -alpha3.7. The data reported here demonstrate that a considerable heterogeneity of alpha-thal mutations occurs in the UAE and that the incidence of alpha-thal in the indigenous population is one of the highest in the world. Our clinical data suggest that Hb H disease in the UAE has, in general, a mild to moderate phenotypic presentation.