IllnessThalassaemia alpha

NGS +

The syndromes of alpha-Thalassemia are based on disturbed alpha-globin chain synthesis. The causes are usually deletions of one or more of the four alpha-globin genes (normal: aa/aa, pathological: a-/aa to --/--), more rarely point mutations. The severity of the clinical pictures of the different alpha-Thalassemia subtypes correlates with the number of affected HBA genes. Two alpha-Thalassemias cause severe health problems, especially Hb-Bart hydrops fetalis syndrome (--/--; Hb Bart syndrome, Thalassemia major) and less dramatically, HbH disease (--/a-). Clinically inapparent is the minima form, the alpha-Thalassaemia minor is detected by laboratory chemistry. HbH disease causes significant deviations from the norm in blood count data already in neonates; in adults there is hemolytic anemia. Hb-Bart syndrome is characterized by severe anemia, hepatosplenomegaly, heart defects and urogenital malformations, so that children usually die very early or are stillborn. Inheritance is complex due to four affected loci, expressiveness is variable. If HBA deletions and sequence deviations are excluded, deletions are very rarely detected in the MCS-R2 region 40 kilobases 5`of the HBA gene cluster. Thus, a suspected clinical diagnosis can practically always be excluded by an inconspicuous finding.

(Basic diagnostic genes: HBA1, HBA2)

Reference: https://www.ncbi.nlm.nih.gov/books/NBK1435/

• Alias: Alpha Thalasämie
• Alias: Alpha-thalassemia intermedia
• Allelic: Erythrocytosis 7 (HBA1, HBA2)
• Allelic: Heinz body anemia (HBA1, HBA2)
• Allelic: Hemoglobin H disease, deletional + nondeletional, HbH disease (HBA1, HBA2)
• Allelic: Methemoglobinemia, alpha type (HBA1)
• Thalassemia, alpha- (HBA1)
• Thalassemia, alpha- (HBA2)