Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
Published: September 2024
AI Article Synopsis
Article Abstract
Objectives: To describe rare genetic interactions of α-thalassemia alleles causing Hb H disease and Hb Bart's hydrops fetalis which could lead to diagnostic errors in a routine practice.
Methods: Hematological and molecular characterization were carried out in a Thai family with a risk of having fetus with Hb Bart's hydrops fetalis.
Results: Both parents were found to be the thalassemia intermedia patients associated with unusual forms of Hb H disease. DNA analysis of common α-thalassemia mutations in Thailand identified α-thalassemia (-α) and unknown α-thalassemia in the father and α-thalassemia (--) with unknown α-thalassemia in the mother. Fetal DNA analysis unlikely identified a homozygosity for α-thalassemia (--/--). Further analysis identified that the father carried a rare South African α-thalassemia in combination with α-thalassemia (--/-α), whereas the mother was a patient with Hb H-Queens Park disease (--/αα). The fetus was, in fact, a compound heterozygote for (--/--).
Conclusions: As shown in this study, routine screening for α-thalassemia at prenatal diagnosis in the region should include both common and rare α-thalassemia alleles found in the population to effectively prevent a fatal condition of Hb Bart's hydrops fetalis syndrome.
Thalassemia is an autosomal recessive genetic disorder and a common form of Hemoglobinopathy. It is classified into α-thalassemia and β-thalassemia. This disease is mainly prevalent in tropical and subtropical regions, including southern China.
In southern China, α-thalassemia is the most prevalent hereditary monogenic disorder, and deletion variants are the predominant form. Conventional thalassemia diagnosis techniques are numerous, however they are all limited in their ability to detect rare deletions. Here, we discuss a family who sought genetic counseling during their fourth pregnancy after experiencing Hb Bart's hydrops fetalis in two of their previous pregnancies.
Objective: Presentation of a novel case of a patient with Hb Bart's hydrops fetalis, which was accurately identified by SMRT sequencing leading to expand the mutation spectrum of α-thalassemia.
Case Report: A 26-year-old pregnant woman and her husband underwent molecular analysis of thalassemia due to abnormal hematological results. The molecular analysis showed that the pregnant woman carried -α/--, while her husband exhibited a negative result.
Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
Objectives: To describe rare genetic interactions of α-thalassemia alleles causing Hb H disease and Hb Bart's hydrops fetalis which could lead to diagnostic errors in a routine practice.
Methods: Hematological and molecular characterization were carried out in a Thai family with a risk of having fetus with Hb Bart's hydrops fetalis.
Results: Both parents were found to be the thalassemia intermedia patients associated with unusual forms of Hb H disease.
α-thalassemia major (α-TM) often causes Hb Bart's (c4) hydrops fetalis and severe obstetric complications in the mother. Step-wise screening for couples at risk of having offspring(s) affected by α-TM is the efficient prevention method but some rare genotypes of thalassemia cannot be detected. A 32-year-old male with low HbA2 (2.
