Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (687 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
A disorder characterized by reduced synthesis of the alpha chains of hemoglobin. The severity of this condition can vary from mild anemia to death, depending on the number of genes deleted.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: alpha-Thalassemias; Thalassemia-alpha; Thalassemia alpha; Hemoglobin H Disease; Disease, Hemoglobin H; Alpha Thalassemia; Thalassemia, Alpha; A-Thalassemia.
Where it fits in the MeSH classification
- Broader topics
- Thalassemia
- Narrower topics
- Hydrops Fetalis
- See also
- Hemoglobin H
Research landscape
PubMed indexes 5,365 records tagged with the MeSH heading “alpha-Thalassemia” (counts retrieved 2026-10-29). 1,099 of them (20.5%) were published from 2020 onward, and the busiest period so far is 2010-2019 with 1,568 records.
Reviews account for 581 records (10.8%) and meta-analyses for 15. Randomized controlled trials number 12 (0.2%) as a share of all records on the topic. Randomized trials make up only a small share of this literature, so much of what is known comes from laboratory, observational or descriptive work.
Show the data
| Period | Records |
|---|---|
| through 1999 | 1,363 |
| 2000-2009 | 1,335 |
| 2010-2019 | 1,568 |
| 2020 onward | 1,099 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 581 | 10.8% |
| Meta-analyses | 15 | 0.3% |
| Randomized controlled trials | 12 | 0.2% |
Method: PubMed query "alpha-Thalassemia"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-29.
Reading the evidence in rare and inherited diseases
Rare conditions are difficult to study: few patients means small studies, case reports and registries are common, and randomized trials are the exception. Small samples limit precision and can exaggerate effects, and cases reported in the literature may be the most severe or unusual. Evidence from many small studies is best read together. Check how patients were identified, how many were included and how long they were followed.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
| Study / authors | Year | Source label / design | Europe PMC citations | Licence / source |
|---|---|---|---|---|
| Zika Virus Infection and Stillbirths: A Case of Hydrops Fetalis, Hydranencephaly and Fetal Demise | 2016 | Research article Design not recorded in structured metadata | 244 | cc by PMID 26914330 · DOI · PMC4767410 |
| Dietary fatty acids fine-tune Piezo1 mechanical response | 2019 | Research article Design not recorded in structured metadata | 239 | cc by PMID 30867417 · DOI · PMC6416271 |
| EPHB4 kinase-inactivating mutations cause autosomal dominant lymphatic-related hydrops fetalis | 2016 | Research article Design not recorded in structured metadata | 86 | cc by PMID 27400125 · DOI · PMC4966301 |
| Mirror Syndrome (Ballantyne Syndrome): Prenatal Diagnosis, Pathophysiology, and the Role of Fetal Therapy-A Narrative Review | 2026 | Review article Design not recorded in structured metadata | 1 | cc by PMID 42531510 · DOI · PMC13571801 |
Zika Virus Infection and Stillbirths: A Case of Hydrops Fetalis, Hydranencephaly and Fetal Demise [1]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundThe rapid spread of Zika virus in the Americas and current outbreak of microcephaly in Brazil has raised attention to the possible deleterious effects that the virus may have on fetuses.
- Closing excerpt
- Given the recent spread of the virus, systematic investigation of spontaneous abortions and stillbirths may be warranted to evaluate the risk that ZIKV infection imparts on these outcomes.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (213 words)
BackgroundThe rapid spread of Zika virus in the Americas and current outbreak of microcephaly in Brazil has raised attention to the possible deleterious effects that the virus may have on fetuses.Methodology/principal findingsWe report a case of a 20-year-old pregnant woman who was referred to our service after a large Zika virus outbreak in the city of Salvador, Brazil with an ultrasound examination that showed intrauterine growth retardation of the fetus at the 18th gestational week. Ultrasound examinations in the 2nd and 3rd trimesters demonstrated severe microcephaly, hydranencephaly, intracranial calcifications and destructive lesions of posterior fossa, in addition to hydrothorax, ascites and subcutaneous edema. An induced labor was performed at the 32nd gestational week due to fetal demise and delivered a female fetus. ZIKV-specific real-time polymerase chain reaction amplification products were obtained from extracts of cerebral cortex, medulla oblongata and cerebrospinal and amniotic fluid, while extracts of heart, lung, liver, vitreous body of the eye and placenta did not yield detectable products.Conclusions/significanceThis case report provides evidence that in addition to microcephaly, there may be a link between Zika virus infection and hydrops fetalis and fetal demise. Given the recent spread of the virus, systematic investigation of spontaneous abortions and stillbirths may be warranted to evaluate the risk that ZIKV infection imparts on these outcomes.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 26914330 · DOI · PMC4767410
Dietary fatty acids fine-tune Piezo1 mechanical response [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Mechanosensitive ion channels rely on membrane composition to transduce physical stimuli into electrical signals.
- Closing excerpt
- Beyond Piezo1, our findings demonstrate that cell-intrinsic lipid profile and changes in the fatty acid metabolism can dictate the cell's response to mechanical cues.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (149 words)
Mechanosensitive ion channels rely on membrane composition to transduce physical stimuli into electrical signals. The Piezo1 channel mediates mechanoelectrical transduction and regulates crucial physiological processes, including vascular architecture and remodeling, cell migration, and erythrocyte volume. The identity of the membrane components that modulate Piezo1 function remain largely unknown. Using lipid profiling analyses, we here identify dietary fatty acids that tune Piezo1 mechanical response. We find that margaric acid, a saturated fatty acid present in dairy products and fish, inhibits Piezo1 activation and polyunsaturated fatty acids (PUFAs), present in fish oils, modulate channel inactivation. Force measurements reveal that margaric acid increases membrane bending stiffness, whereas PUFAs decrease it. We use fatty acid supplementation to abrogate the phenotype of gain-of-function Piezo1 mutations causing human dehydrated hereditary stomatocytosis. Beyond Piezo1, our findings demonstrate that cell-intrinsic lipid profile and changes in the fatty acid metabolism can dictate the cell's response to mechanical cues.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 30867417 · DOI · PMC6416271
EPHB4 kinase-inactivating mutations cause autosomal dominant lymphatic-related hydrops fetalis [3]
Abstract reading summary — source excerpts
- Opening excerpt
- Hydrops fetalis describes fluid accumulation in at least 2 fetal compartments, including abdominal cavities, pleura, and pericardium, or in body tissue.
- Closing excerpt
- Together, these findings identify EPHB4 as a critical regulator of early lymphatic vascular development and demonstrate that mutations in the gene can cause an autosomal dominant form of LRHF that is associated with a high mortality rate.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (182 words)
Hydrops fetalis describes fluid accumulation in at least 2 fetal compartments, including abdominal cavities, pleura, and pericardium, or in body tissue. The majority of hydrops fetalis cases are nonimmune conditions that present with generalized edema of the fetus, and approximately 15% of these nonimmune cases result from a lymphatic abnormality. Here, we have identified an autosomal dominant, inherited form of lymphatic-related (nonimmune) hydrops fetalis (LRHF). Independent exome sequencing projects on 2 families with a history of in utero and neonatal deaths associated with nonimmune hydrops fetalis uncovered 2 heterozygous missense variants in the gene encoding Eph receptor B4 (EPHB4). Biochemical analysis determined that the mutant EPHB4 proteins are devoid of tyrosine kinase activity, indicating that loss of EPHB4 signaling contributes to LRHF pathogenesis. Further, inactivation of Ephb4 in lymphatic endothelial cells of developing mouse embryos led to defective lymphovenous valve formation and consequent subcutaneous edema. Together, these findings identify EPHB4 as a critical regulator of early lymphatic vascular development and demonstrate that mutations in the gene can cause an autosomal dominant form of LRHF that is associated with a high mortality rate.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 27400125 · DOI · PMC4966301
Mirror Syndrome (Ballantyne Syndrome): Prenatal Diagnosis, Pathophysiology, and the Role of Fetal Therapy-A Narrative Review [4]
Abstract reading summary — source excerpts
- Opening excerpt
- Mirror syndrome is a rare maternal-fetal condition associated with fetal hydrops and a high risk of adverse maternal and fetal perinatal outcomes.
- Closing excerpt
- Early recognition and multidisciplinary management are essential to optimize maternal and fetal outcomes.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (143 words)
Mirror syndrome is a rare maternal-fetal condition associated with fetal hydrops and a high risk of adverse maternal and fetal perinatal outcomes. Its diagnosis is challenging due to the lack of standardized diagnostic criteria and its clinical and biochemical overlap with preeclampsia. This narrative review summarizes current evidence on mirror syndrome, with a focus on prenatal diagnosis, placental pathophysiology and the role of targeted fetal therapy. Mirror syndrome is most frequently associated with non-immune causes of fetal hydrops and available evidence supports a central role for the placenta in disease pathogenesis. Recent data suggest that angiogenic biomarkers, including sFlt-1 and PlGF, may be useful in the differential diagnosis from preeclampsia. Resolution of fetal hydrops through in utero therapy can lead to rapid maternal improvement and pregnancy prolongation in selected cases. Early recognition and multidisciplinary management are essential to optimize maternal and fetal outcomes.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42531510 · DOI · PMC13571801
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article Alpha-thalassaemia [5]
- Research article The α-thalassemias [6]
- Research article Alpha and beta thalassemia [7]
- Research article Hemoglobin H disease: not necessarily a benign disorder [8]
- Research article Society for maternal-fetal medicine (SMFM) clinical guideline #7: nonimmune hydrops fetalis [9]
- Research article ATRX and DAXX: Mechanisms and Mutations [10]
References
- Sarno M, Sacramento GA, Khouri R, do Rosário MS, Costa F, Archanjo G, et al.. Zika Virus Infection and Stillbirths: A Case of Hydrops Fetalis, Hydranencephaly and Fetal Demise. . 2016. PMID 26914330 · DOI · PMC4767410
- Romero LO, Massey AE, Mata-Daboin AD, Sierra-Valdez FJ, Chauhan SC, Cordero-Morales JF, et al.. Dietary fatty acids fine-tune Piezo1 mechanical response. . 2019. PMID 30867417 · DOI · PMC6416271
- Martin-Almedina S, Martinez-Corral I, Holdhus R, Vicente A, Fotiou E, Lin S, et al.. EPHB4 kinase-inactivating mutations cause autosomal dominant lymphatic-related hydrops fetalis. . 2016. PMID 27400125 · DOI · PMC4966301
- Tudisco R, Latapie P, Romiti A, Benachi A, Abgral M, Vivanti AJ. Mirror Syndrome (Ballantyne Syndrome): Prenatal Diagnosis, Pathophysiology, and the Role of Fetal Therapy-A Narrative Review. . 2026. PMID 42531510 · DOI · PMC13571801
- Harteveld CL, Higgs DR. Alpha-thalassaemia. Orphanet J Rare Dis. 2010. PMID 20507641 · DOI · PMC2887799
- Piel FB, Weatherall DJ. The α-thalassemias. N Engl J Med. 2014. PMID 25390741 · DOI
- Muncie HL, Campbell J. Alpha and beta thalassemia. Am Fam Physician. 2009. PMID 19678601
- Chui DH, Fucharoen S, Chan V. Hemoglobin H disease: not necessarily a benign disorder. Blood. 2003. PMID 12393486 · DOI
- Society for Maternal-Fetal Medicine (SMFM), Norton ME, Chauhan SP, Dashe JS. Society for maternal-fetal medicine (SMFM) clinical guideline #7: nonimmune hydrops fetalis. Am J Obstet Gynecol. 2015. PMID 25557883 · DOI
- Dyer MA, Qadeer ZA, Valle-Garcia D, Bernstein E. ATRX and DAXX: Mechanisms and Mutations. Cold Spring Harb Perspect Med. 2017. PMID 28062559 · DOI · PMC5334245
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-29.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.