Association between α-globin gene copy number and NO-related vascular phenotypes
| Cohort and α-thalassemia genotype . | Phenotype . | Findings . | Reference . |
|---|---|---|---|
| 282 individuals with SCD ±1 or 2 −α3.7 HBA alleles | Pulmonary hypertension | No association | 28 |
| 623 African adolescents in Nairobi, Kenya ±1 or 2 −α3.7 alleles | Blood pressure | No association | 98 |
| 8947 AA in REGARDS cohort∗ | Ischemic stroke | No association | 25 |
| 9684 AA in REGARDS cohort | Hypertension | No association | 26 |
| 9908 AA in REGARDS cohort | Kidney disease | Prevalence of chronic and end-stage kidney disease increased with HBA gene copy number from 2 to 6 | 27 |
| 37 patients with SCA; 19 with 1 or 2 −α3.7 alleles | Microvascular blood flow to skin | No association at baseline. Increased blood flow after local heating associated with 1 or 2 −α3.7 alleles | 24 |
| 27 AA and Asian individuals: 15 with 1 or 2α-globin gene deletions | FMD | Increased FMD associated with 1 or 2 α3.7 alleles | 23 |
| Cohort and α-thalassemia genotype . | Phenotype . | Findings . | Reference . |
|---|---|---|---|
| 282 individuals with SCD ±1 or 2 −α3.7 HBA alleles | Pulmonary hypertension | No association | 28 |
| 623 African adolescents in Nairobi, Kenya ±1 or 2 −α3.7 alleles | Blood pressure | No association | 98 |
| 8947 AA in REGARDS cohort∗ | Ischemic stroke | No association | 25 |
| 9684 AA in REGARDS cohort | Hypertension | No association | 26 |
| 9908 AA in REGARDS cohort | Kidney disease | Prevalence of chronic and end-stage kidney disease increased with HBA gene copy number from 2 to 6 | 27 |
| 37 patients with SCA; 19 with 1 or 2 −α3.7 alleles | Microvascular blood flow to skin | No association at baseline. Increased blood flow after local heating associated with 1 or 2 −α3.7 alleles | 24 |
| 27 AA and Asian individuals: 15 with 1 or 2α-globin gene deletions | FMD | Increased FMD associated with 1 or 2 α3.7 alleles | 23 |
AA, African Americans; SCA, sickle cell anemia.
REGARDS (“Reasons for Geographic and Racial Differences in Stroke”)97 including 8947 to 9908 eligible AA with HBA copy number of 2 (4%), 3 (28%), 4 (67%), or ≥5 (1%).