Application of electrospray triple quadrupole mass spectrometry in assessing thalassemia in a population

Thalassemia is widely prevalent in Asian countries and the Middle East region of the world. While the prevalence of α thal is around 5-20% in the population, the incidence of β thal is around 3-4%. The available data on thalassemia in Indians is based on chromatographic or electrophoretic techniques. The present study demonstrates the utility of mass spectrometry in detecting thalassemia in a small, healthy population from Tiptur, Karnataka.

The study included a population of 315 individuals, spanning both children and adults, with ages ranging from 4 to 76 years. EDTA whole blood was collected after obtaining their written consent. The intensities of various globin chains were measured using a triple quadrupole mass spectrometer. The ratio of the peak areas of globin chains (α/β, δ/β (%)) served as biomarkers to detect thalassemia. Thirty random samples of α thalassemia were analyzed using GapPCR.

The prevalence of α thal is 21.65% (68/314) based on α/β (< =0.8) and the prevalence of β thal is 3.8% (12/314) based on δ/β (%) (> =11.0). GapPCR detected three heteromutants of α deletion, one mutation in the HBA1 gene, and one α triplication (16.7%, 5/30). One sample was excluded from the analysis due to the presence of a variant.

The utility of mass spectrometry for screening thalassemia in a population is demonstrated. The higher occurrence of α-thalassemia in the studied population underscores the importance of screening for thalassemia in regions with reportedly high prevalence rates.