Alpha thalassaemia in Sardinian newborns

Area of Science:

• Hematology
• Genetics
• Newborn Screening

Background:

• Alpha-thalassemia is a common inherited blood disorder.
• Accurate genotype-phenotype correlation is crucial for understanding disease expression.
• Hb Bart's levels at birth are a key indicator of alpha-thalassemia.

Purpose of the Study:

• To investigate the correlation between hematological parameters and alpha-globin genotypes in Sardinian newborns.
• To analyze the impact of different alpha-thalassemia genotypes on red cell indices and Hb Bart's levels.
• To assess the influence of co-inherited beta 0-thalassemia on alpha-thalassemia expression at birth.

Main Methods:

• Analysis of hematological parameters including red cell indices and Hb Bart's levels.
• Genotyping of alpha-globin genes in newborns.
• Correlation of genotypic data with phenotypic findings.

Main Results:

• Infants with two deleted alpha-globin genes exhibited microcytosis, low MCH, and Hb Bart's levels between 2.0-7.1%.
• A significant portion (61.1%) of infants with the (- alpha/ alpha alpha) genotype were phenotypically silent, while 38.9% showed minimal microcytosis and detectable Hb Bart's (0.78-2.5%).
• Non-deletion alpha-thalassemia genotypes presented Hb Bart's levels similar to the (- alpha / alpha alpha) genotype, and co-inherited heterozygous beta 0-thalassemia did not affect alpha-thalassemia expression at birth.

Conclusions:

• Specific alpha-globin genotypes have distinct correlations with hematological parameters in newborns.
• The phenotypic expression of alpha-thalassemia can vary, with some genotypes being silent.
• Co-inheritance of beta 0-thalassemia does not appear to modify the expression of alpha-thalassemia at birth in this population.