Hemoglobin H disease: genes and variants
Hemoglobin H disease is linked to 1 analyzed protein (HBA1). 6 DNA variants are known to cause it; 1 more are uncertain, and 0 of those already look disease-causing on computable evidence.
Last updated 2026-09-30. Research information, not medical advice.
Genes linked to Hemoglobin H disease
HBA1: Hemoglobin subunit alpha
It contributes alpha-globin chains that pair with beta-like globins to carry oxygen in red blood cells. Deletion or inactivation reduces alpha-globin production and causes alpha-thalassemia, with severity determined by the number and function of affected alpha-globin genes.
6 disease-causing and 1 uncertain variants in HBA1 are linked to Hemoglobin H disease.
Known disease-causing variants in Hemoglobin H disease
| Variant | Position | Protein part | Clinical label |
|---|---|---|---|
| HBA1 G60D | 60 | Globin | Disease-causing (★★) |
| HBA1 W15R | 15 | Globin | Disease-causing (★★) |
| HBA1 M33I | 33 | Globin | Disease-causing (★★) |
| HBA1 A111D | 111 | Globin | Disease-causing (★★) |
| HBA1 P120S | 120 | Globin | Disease-causing (★★) |
| HBA1 L130P | 130 | Globin | Disease-causing (★★) |
Same protein, different disease
- Erythrocytosis, familial, 6 is also caused by HBA1 variants; they fall mostly in different places as the Hemoglobin H disease variants (16 disease-causing).
- Alpha Thalassemia is also caused by HBA1 variants; they fall partly in the same places as the Hemoglobin H disease variants (10 disease-causing).
- Heinz body anemia is also caused by HBA1 variants; they fall mostly in different places as the Hemoglobin H disease variants (7 disease-causing).
Diseases related to Hemoglobin H disease
- Erythrocytosis, familial, 6, also linked to HBA1
- Heinz body anemia, also linked to HBA1
- Alpha Thalassemia, also linked to HBA1
- Primary familial polycythemia due to EPO receptor mutation, also linked to HBA1
Frequently asked questions
Which genes are linked to Hemoglobin H disease?
In CATVariant, Hemoglobin H disease is linked to 1 analyzed protein: HBA1 (Hemoglobin subunit alpha).
How many genetic variants are linked to Hemoglobin H disease?
11 variants: 6 are classified as disease-causing (pathogenic or likely pathogenic) in ClinVar and 1 are of uncertain significance or have conflicting reports.
Which uncertain variants in Hemoglobin H disease look disease-causing?
None of the uncertain variants currently reaches the likely-pathogenic range on computable evidence alone.
About this data
Variant–disease links come from ClinVar, Open Targets and UniProt, pooled from the latest public CATVariant analysis of each human protein. Evidence scores use the ACMG/AMP Bayesian points scale with computable criteria only (position among known disease variants, rarity in gnomAD, calibrated predictors, deep mutational scanning); there is no family or patient data, so they prioritise variants for expert review and never classify them.
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