Heterozygous Anti-3.7 HBA Rearrangement

**Semantic type:** Cell or Molecular Dysfunction

**Definition:** A complex cytogenetic abnormality where one copy of chromosome 16 has undergone chromosomal rearrangement in the vicinity of 16p13.3, which is the region containing the 2 genes that encode hemoglobin subunit alpha (HBA; alpha-globin), HBA1 and HBA2. This rearrangement results in amplification of a 3.7 kb fragment containing of one of the HBA genes (usually HBA2) and may lead to simultaneous deletion of the other HBA gene (usually HBA1).

**Synonyms:** - Alpha Alpha Alpha Anti-3,7/Alpha Alpha - Alpha-Globin Gene Duplication - HBA Triplication - HBA1 - HBA triplication (aaaanti-3.7 / aa) - Heterozygous Alpha Alpha Alpha Anti-3,7 - Monozygotic Alpha Globin Gene Amplification - Monozygotic HBA Gene Amplification - Monozygotic Hemoglobin Subunit Alpha Gene Amplification - aaaanti-3.7 / aa