Alpha thalassemia genotypes in Kuwait.

Area of Science:

• Medical Genetics
• Hematology
• Population Genetics

Background:

• Alpha thalassemia trait is highly prevalent in Kuwait (approx. 40%).
• A comprehensive study of prevalent alpha thalassemia alleles was lacking.
• This study reports molecular diagnoses over a 20-year period.

Purpose of the Study:

• To identify and characterize the prevalent alpha thalassemia alleles in the Kuwaiti population.
• To understand the genetic basis of alpha thalassemia in Kuwait.
• To inform genetic counseling and public health strategies.

Main Methods:

• Retrospective analysis of α-globin genotypes from 1994-2015.
• Molecular genotyping using PCR and hybridization techniques (Vienna Lab Strip Assay).
• Analysis of 400 samples from individuals across a wide age range.

Main Results:

• The polyadenylation-1 (PA-1) mutation was the most frequent allele (0.59), found in homozygosity (33.3%) and heterozygosity (32.3%).
• The α⁰ (--^MED) allele occurred with a frequency of 0.017.
• Rare alleles including α⁰ (--^FIL), Hb Constant Spring, Hb Adana, and Hb Icaria were identified.

Conclusions:

• Nondeletional PA-1 is the primary cause of moderate to severe HbH disease in Kuwait.
• The presence of α⁰ (--^MED) necessitates careful premarital counseling to address risks of alpha thalassemia major (Barts hydrops fetalis).
• A diverse range of alpha thalassemia alleles exists in Kuwait, with PA-1 being predominant.