Ugrás a tartalomhoz
Használja fel HSA- vagy FSA-keretét

Betegségjelentés · Hematological

Thalassemia

Whole genome sequencing reads the complete alpha-globin (HBA1/HBA2) and beta-globin (HBB) gene clusters, resolving every deletion, point mutation, and compound heterozygous combination: the full architecture that standard carrier screens do not characterize.

A betegségjelentés olyan ritka variánsokat keres, amelyekről ismert, hogy okozzák az általa lefedett betegségeket.

A Premium és a Premium + AI csomagban benne van

A Premium első évre készletenként 99 $ díjjal jár.

Rendelés Premium csomaggal

A(z) condition ismertetése

Inherited blood disorders in which the body makes too little haemoglobin, due to variants in the alpha-globin (HBA1, HBA2) or beta-globin (HBB) genes. Severity ranges from carriers with no symptoms to severe anaemia needing regular transfusions.

Thalassemia syndromes are autosomal recessive hemoglobinopathies caused by reduced or absent production of alpha- or beta-globin chains, leading to imbalanced globin chain synthesis, ineffective erythropoiesis, and chronic hemolytic anemia. Collectively, thalassemias are the most common single-gene disorders worldwide: an estimated 270 million people carry a thalassemia variant, and approximately 60,000 severely affected children are born annually. Thalassemia carrier frequencies are highest in malaria-endemic regions: the Mediterranean, sub-Saharan Africa, the Middle East, South and Southeast Asia, and southern China.

Alpha-thalassemia is caused by deletions or mutations affecting the HBA1 and HBA2 genes on chromosome 16p13.3. Because there are four alpha-globin gene copies (two HBA1 and two HBA2 on each chromosome 16), alpha-thalassemia severity follows a dosage-dependent gradient: one gene deleted (alpha-thalassemia silent carrier), two genes deleted (alpha-thalassemia trait), three genes deleted (HbH disease, moderate anemia), four genes deleted (Hb Bart's hydrops fetalis, uniformly fatal in utero without intervention). Beta-thalassemia is caused by point mutations or small insertions/deletions in the HBB gene. Beta-thalassemia major (Cooley's anemia, beta⁰/beta⁰) requires lifelong transfusion; beta-thalassemia intermedia has variable severity; beta-thalassemia trait is asymptomatic.

The genetic architecture of thalassemia is among the most complex of any Mendelian disorder. Over 300 beta-globin variants and dozens of alpha-globin deletion types have been characterized. Compound heterozygosity (inheriting different thalassemia variants from each parent) creates phenotypes not predictable from either variant alone. Co-inheritance of alpha- and beta-thalassemia modifies disease severity: concurrent alpha-thalassemia reduces globin chain imbalance in beta-thalassemia, paradoxically ameliorating the condition. Gene therapy (betibeglogene autotemcel, approved 2022) and gene editing (exagamglogene autotemcel/exa-cel, approved 2023) offer curative potential for transfusion-dependent patients, making definitive genotyping directly treatment-enabling.

Alpha- and beta-thalassemia involve different genes and inheritance patterns. Compound heterozygous combinations create distinct clinical phenotypes not predictable from individual variant testing alone.

A vizsgált 2 betegség

Thalassemia

A group of inherited haemoglobin disorders caused by reduced or absent synthesis of alpha- or beta-globin chains.

Mit változtat a diagnózis

Transfusion and iron chelation (thalassemia major); hydroxyurea; betibeglogene autotemcel (Zynteglo) and exagamglogene autotemcel (Casgevy) gene therapy for transfusion-dependent disease; hematopoietic stem cell transplantation

Vizsgált gének

Más néven

sickle-cell thalassemia with crisis; sickle-cell thalassemia without crisis

15 kapcsolódó altípust tartalmaz ↓
  • alpha thalassemia spectrum
  • beta thalassemia
  • beta-thalassemia HBB/LCRB
  • beta-thalassemia intermedia
  • beta-thalassemia major
  • digenic alpha thalassemia spectrum
  • dominant beta-thalassemia
  • Hb Bart's hydrops fetalis
  • HBA1-related alpha thalassemia spectrum
  • HBA1; HBA2-related digenic alpha thalassemia spectrum
  • HBA2-related alpha thalassemia spectrum
  • hemoglobin H disease
  • monogenic alpha thalassemia spectrum
  • thalassemia minor
  • thalassemia, beta+, silent allele
MONDO:0000984MedGen 21121

Beta-Thalassaemia and Related Disorders

Autoszomális recesszív

Disorders of beta-globin production, including beta-thalassaemia, haemoglobin E-beta-thalassaemia, delta-beta-thalassaemia and haemoglobin Lepore, ranging from carrier states with mild anaemia to transfusion-dependent disease.

Mit változtat a diagnózis

Carrier status is relevant to family planning, and affected people may need transfusions, iron chelation or newer treatments.

Vizsgált gének

13 kapcsolódó altípust tartalmaz ↓
  • beta thalassemia
  • beta-thalassemia HBB/LCRB
  • beta-thalassemia intermedia
  • beta-thalassemia major
  • beta-thalassemia-X-linked thrombocytopenia syndrome
  • delta-beta-thalassemia
  • dominant beta-thalassemia
  • hemoglobin C-beta-thalassemia syndrome
  • hemoglobin E-beta-thalassemia syndrome
  • hemoglobin Lepore-beta-thalassemia syndrome
  • hereditary persistence of fetal hemoglobin-beta-thalassemia syndrome
  • thalassemia minor
  • thalassemia, beta+, silent allele
MONDO:0017145Orphanet 275749MedGen 1826095

Miért a teljes genom szekvenálás

Standard carrier screening tests for common regional thalassemia variants. It cannot resolve the full alpha-globin deletion genotype, compound heterozygous states, or modifier loci that determine clinical severity and reproductive risk.

Alpha-globin gene copy number requires genome-level resolution; SNP panels cannot determine it

Alpha-thalassemia is predominantly caused by large deletions that remove one or both alpha-globin genes from a chromosome. Determining the number of residual functional alpha-globin gene copies (the primary determinant of clinical severity) requires deletion mapping with breakpoint characterization. SNP-based carrier screening panels do not detect gene deletions. Even targeted deletion testing (MLPA, Gap-PCR) evaluates only the most common regional deletion types and may miss rare or atypical deletions. Whole genome sequencing maps all alpha-globin deletions, determines precise gene copy number, and characterizes breakpoints, the information required to distinguish alpha-thalassemia trait ('cis' vs 'trans' deletion configurations) and predict hydrops fetalis risk.

Gene therapy eligibility requires the definitive genotype, not a screening result

The approval of betibeglogene autotemcel (Zynteglo, 2022) and exa-cel (Casgevy, 2023) for transfusion-dependent beta-thalassemia has made definitive HBB genotyping directly treatment-enabling. Gene therapy eligibility criteria specify the beta-thalassemia genotype and, in some protocols, exclude certain variant types. For patients being evaluated for curative gene therapy or gene editing, the complete globin genotype (including identification of any co-inherited alpha-thalassemia that may affect the treatment response) must be established with certainty. Whole genome sequencing provides this definitive genotype in a single, comprehensive test.

További hematological conditions

Minden feltétel →

Egy teszt. Egy életen át tartó válaszok.

Egy csomag, házhoz szállítva. Az egész genomját a diagnosztikai döntésekhez használt klinikai színvonalon szekvenáljuk. Orvos számára is használható jelentéseit 6–8 héten belül küldjük el a Genome Manager-be. Ezek tartósan érvényesek, és a tudomány fejlődésével frissülnek.

449 $-tól

Ingyenes szállítás · Eredmények 6–8 hét alatt

A Premium első évre készletenként 99 $ díjjal jár.

Rendelés Premium csomaggal