HemoglobinopatHemoglobinopathieshies

HemoglobinopatHemoglobinopathieshies

Disorders of Disorders of HemoglobinHemoglobin

Dr. Pupak DerakhshandehDr. Pupak Derakhshandeh

Disorders of Disorders of HemoglobinHemoglobin

5 % of world population: 5 % of world population: carrier for genes, carrier for genes, important disorders of important disorders of hemoglobinhemoglobin

Structure and Structure and function of function of hemoglobinhemoglobin

Oxygen carrierOxygen carrier In vertebrate: red In vertebrate: red blood blood cellscells

Four subunits: Four subunits: 22αα- and 2- and 2-chains-chains

HemoglobinHemoglobin

Each SubunitsEach Subunits

Globin: Polypeptide chainGlobin: Polypeptide chain Heme : Prosthetic groupHeme : Prosthetic group

(Iron-Containing (Iron-Containing pigment)pigment)

Heme + OxygeneHeme + OxygeneOxygene transportingOxygene transporting

Normal adult Normal adult hemoglobinhemoglobin

HbAHbA::

22 αα globin chain (141 AA) globin chain (141 AA) 2 2 globin chain (146 AA) globin chain (146 AA) αα2222

Equal lengthEqual length

Normal adult Normal adult hemoglobinhemoglobin

HbFHbF::

22 αα globin chain globin chain 2 2 γγ globin chain globin chain αα22γγ22

Normal adult Normal adult hemoglobinhemoglobin

Hemoglobin in the Hemoglobin in the OntogenesisOntogenesis

ThalassemiThalassemiaa Onset: ChildhoodOnset: Childhood

Hypo chromic / Microcrystal Hypo chromic / Microcrystal anemiaanemia

Low level of MCV / MCHLow level of MCV / MCHMean corpuscular volume (MCV)Mean corpuscular hemoglobin (MCH)

-Thal: Elevated HbA-Thal: Elevated HbA2 2 ((αα2222))

HbF (HbF (αα22γγ22)) αα-Thal: Normal HbA-Thal: Normal HbA22, HbF , HbF

Thalassemia Thalassemia MinorMinor

Thalassemia MinorThalassemia Minor

• Thalassemia minor is an inherited form of hemolytic anemia that is less severe than thalassemia major.

• This blood smear from an individual with thalassemia shows small (microcytic), pale (hypochromic), variously-shaped red blood cells.

• These small red blood cells (RBCs) are able to carry less oxygen than normal RBCs.

Thalassemia Thalassemia MajorMajor

an inherited form of hemolytic anemia

red blood cell (hemoglobin) abnormalities

the most severe form of anemia

the oxygen depletion in the body becomes apparent within the first 6 months of life

Thalassemia major

If untreated, death usually results within a few years

Note the small, pale (hypochromic), abnormally-shaped red blood cells associated with thalassemia major

The darker cells likely represent normal RBCs from a blood transfusion

DieseaseDiesease Autosomal recessive Autosomal recessive Deficiency: Synthesis of Deficiency: Synthesis of

αα//- - globinglobin Origin: Mediteranean, Origin: Mediteranean,

African, African, Iranian, Indian, Iranian, Indian, Southeast Southeast AsianAsian

Resistant to malariaResistant to malaria

Prevalence of Prevalence of αα--ThalassemiaThalassemia

0.01 % in non malarial 0.01 % in non malarial areasareas

ig. UK, Japanig. UK, Japan ~ 49 % in Soutwest ~ 49 % in Soutwest

Pasific Pasific IslandsIslands

Defected globin Defected globin chainschains

Prevalence of Prevalence of --ThalassemiaThalassemia

~ 1.5 % in Africans and ~ 1.5 % in Africans and African AmericansAfrican Americans

~ 30 % in Sardinia~ 30 % in Sardinia

Pathogenesis Pathogenesis of of -Thalassemia-Thalassemia

In adequate Hb production Reduced MCV/MCH

Unbalanced accumulation of globin subunits Ineffective Erythrocyt

200 different mutations In Iran about 60 mutations

αα globin globin mutationsmutations

Deletions: 80-85 % of Deletions: 80-85 % of ααThalassemiaThalassemiaDel: 3.7 kb (most frequent)Del: 3.7 kb (most frequent)Del: 4.2 kbDel: 4.2 kb

αα22 InsI-5bp deletion ( InsI-5bp deletion (ααHph1Hph1αα))

αα22 InCd T>C ( InCd T>C (ααNco1Nco1αα))

α১ Variant:Variant:--MED--MED--CAL--CAL--SEA--SEA

-Thalassemia-Thalassemia Trait -

– Hemoglobin is with in the reference range.

– Reticulocyte count is within the reference range.

– Mean corpuscular volume (MCV) is 75-85 fL.

– Mean corpuscular hemoglobin (MCH) is 26 pg.

a-Thalassemiaa-Thalassemia Alpha1 thalassemia minor (--/)

– Hemoglobin is within the reference range.

– Reticulocyte count is within the reference range.

– MCV is 65-75 fL.– MCH is 22 pg.

Hemoglobin H diseaseHemoglobin H disease

Peripheral smear from a patient with hemoglobin H disease showing target cells, microcytosis and hypochromia. Morphological abnormalities are similar to those observed in beta thalassemia. In alpha2 thalassemia (silent trait) only mild microcytosis is observed.

HbH diseaseHbH disease•Hemoglobin H disease

– Hemoglobin is 7-10 g/dL.– Reticulocyte count is 5-10%.– MCV is 55-65 fL.– MCH is 20 pg.– The peripheral blood smear shows

small misshapen red cells, hypochromia, microcytosis, and targeting.

– Brilliant cresyl blue stain demonstrates hemoglobin H inclusion bodies.

HbH diseaseHbH disease

Functional Functional αα globinglobin : 1: 1 αα:: globin ratio : 0.3 globin ratio : 0.3 Hb level: 7-9 g/dlHb level: 7-9 g/dl Genotype: --/-Genotype: --/-αα HbH Inclusion (Heinz body): ManyHbH Inclusion (Heinz body): Many Moderate anemiaModerate anemia HepatosplenomegalyHepatosplenomegaly Galstones, infection, folic acid Galstones, infection, folic acid

deficiencydeficiency

Hydrops fetalisHydrops fetalis

–Hemoglobin is 4-10 g/dL. –MCV is 110-120 fL. –The peripheral blood smear shows severe hypochromia, and nucleated red blood cells.

Hydrops fetalisHydrops fetalis

Functional Functional αα globinglobin : 0: 0 αα:: globin ratio : 0.0 globin ratio : 0.0 Genotype: --/--Genotype: --/-- HbH Inclusion (Heinz body): HbH Inclusion (Heinz body):

PresentPresent Severe anemiaSevere anemia Heart defect/fatal in utero/Heart defect/fatal in utero/

shortly after birthshortly after birth

TreatmentTreatment• Avoid iron supplementation. It contributes to

iron overload • Administer folate supplementation to provide

adequate amounts of the vitamin for increased utilization resulting from the hemolytic process and high bone marrow turnover rate.

• Provide prompt attention to infection, especially in children who have had a splenectomy.

• Administer blood transfusions only if necessary.• If chronic transfusion is needed (hemoglobin H

disease), iron chelation therapy should be considered to avoid iron overloading.

Surgical CareSurgical CareHemoglobin H disease

– Perform a splenectomy if transfusion requirements are increasing.

– Surgical or orthodontic correction may be necessary to correct skeletal deformities of the skull and maxilla due to erythroid hyperplasia.

globin mutationsglobin mutations

1.1. Transcriptional mutations Transcriptional mutations ((++))

In promotor regulatory In promotor regulatory elementselements -101(silent)-101(silent) -92 (silent)-92 (silent) -88-88 -30-30

globin globin mutationsmutations

2.2. RNA-Processing ( RNA-Processing (ºº)) Splice junctionSplice junction

IVSI-1 Cd30IVSI-1 Cd30 IVSI-2 IVSI-2 IVSI-3’ end del 25bpIVSI-3’ end del 25bp IvsI-130IvsI-130

Consensus splice sites Consensus splice sites ((º/ º/ ++)) IVSI-5IVSI-5 IVSI-6IVSI-6 IVSII-844IVSII-844

globin mutationsglobin mutations

Cryptic splice sites in Introns Cryptic splice sites in Introns ((++)) IVSI-110IVSI-110 IVSII-745IVSII-745

Cryptic splice sites in exonsCryptic splice sites in exons Cd 26 (HbE)Cd 26 (HbE) Cd 121 (HbD panjab/O Arab)Cd 121 (HbD panjab/O Arab)

-Thalassemia -Thalassemia majormajor

Onset: 6 monthsOnset: 6 months Severe hemolytic anemiaSevere hemolytic anemia Hb level< 7 g/dlHb level< 7 g/dl Skin: paleSkin: pale Growth retardationGrowth retardation don’t eat or sleep welldon’t eat or sleep well HepatosplenomegalyHepatosplenomegaly Bone marrow expansion:Bone marrow expansion:

Make more red cellsMake more red cells Expantion in face and skullExpantion in face and skull Spleen: destroy of young red cellSpleen: destroy of young red cell 80% of untreated patients: † by 5 y.80% of untreated patients: † by 5 y. Treatment: Cardiac/Hepatic: † by 30 y.Treatment: Cardiac/Hepatic: † by 30 y. Transfusion +Chelation > 30yTransfusion +Chelation > 30y..

Thalassemia majorThalassemia major

Thalassemia majorThalassemia major

TreatmentTreatment Blood transfusion (3-4 weeks for Blood transfusion (3-4 weeks for

life)life)Iron accumulation in bodyIron accumulation in body

Remove the iron: Desferal:Remove the iron: Desferal:Infused under the skin (8-12 h/6 Infused under the skin (8-12 h/6

times a week)times a week) Bone marrow transplantationBone marrow transplantation

A sib brother or sisterA sib brother or sisterHLA matchedHLA matched

Sickle Cell disorderSickle Cell disorder

Sickle Cell disorderSickle Cell disorder

Stuck the red cell in the vesselsStuck the red cell in the vessels In children: Spleen, chest, In children: Spleen, chest,

wrists,ankleswrists,ankles In adults: hips and shouldersIn adults: hips and shoulders Anemia (Hb 7-8 g/dl)Anemia (Hb 7-8 g/dl) Infections (take antibiotics)Infections (take antibiotics) Painful crises (6-18 months)Painful crises (6-18 months) Swollen and inflamed (hand/food Swollen and inflamed (hand/food

syndrome)syndrome)

What are the What are the Complications?Complications?

• pain episodes • increased infections • bone damage • yellow eyes or jaundice • early gallstones • lung blockage • kidney damage and loss of body water in

urine • painful erections in men (priapism) • blood blockage in the spleen or liver

(sequestration) • eye damage • low red blood cell counts (anemia) • delayed growth

Prenatal diagnosisPrenatal diagnosis

I. ARMS-PCR (22 common I. ARMS-PCR (22 common mut.)mut.)

II. PCR-RFLP (9 inf. RFLPs)II. PCR-RFLP (9 inf. RFLPs)

III. RDB (60 mut.)III. RDB (60 mut.)

IV. SequencingIV. Sequencing

ARMS-PCRARMS-PCR

1 2 3 4 5 6 7 8 9 10 11 12 13

PCR-RFLPPCR-RFLP1 2 3 M 4 5 6 7

The combination of The combination of hemoglobinopathieshemoglobinopathies

Doesn't cause any health Doesn't cause any health problem:problem: αα+ + Thalassemia / Thalassemia / αα+ + ThalassemiaThalassemia

HbH disease:HbH disease: ααº º Thalassemia / Thalassemia / αα+ + ThalassemiaThalassemia

Hydrops fetalis:Hydrops fetalis: ααº º Thalassemia / Thalassemia / ααº º ThalassemiaThalassemia

Doesn't cause any Doesn't cause any health problemhealth problem

αα+ / º + / º

Thalassemia/Thalassemia/ThalassemiaThalassemia αα+ / º + / º Thalassemia / HbCThalassemia / HbC αα+ / º + / º Thalassemia / HbDThalassemia / HbD αα+ / º + / º Thalassemia / HbEThalassemia / HbE αα+ / º + / º Thalassemia / HbO ArabThalassemia / HbO Arab αα+ / º + / º Thalassemia / HbSThalassemia / HbS

Thalassemia / Thalassemia / ThalassemiaThalassemia

Caused severe Caused severe health health problem!problem!

Other Other combinationscombinations

HbC / HbC / Thalassemia (no problem)Thalassemia (no problem) HbD / HbD / Thalassemia (no problem)Thalassemia (no problem) HbE / HbE / Thalassemia (serious anemia)Thalassemia (serious anemia) Hbs / Hbs / Thalassemia (intermediate-Thalassemia (intermediate-

severe)severe) HPFH* / HPFH* / Thalassemia (no problem)Thalassemia (no problem)

*Heriditary persistance of fetal hemoglobin*Heriditary persistance of fetal hemoglobin

Doesn't cause any Doesn't cause any health problemhealth problem

HbC / HbCHbC / HbC HbC / D, E, O Arab, HPFHHbC / D, E, O Arab, HPFH

HbD / HbDHbD / HbD HbD / C, E, O Arab, HPFHHbD / C, E, O Arab, HPFH

HbE / HbEHbE / HbE HbE / C, D, O Arab, HPFHHbE / C, D, O Arab, HPFH

Doesn't cause any Doesn't cause any health problemhealth problem

HbO Arab / HbO ArabHbO Arab / HbO Arab HbO Arab/ C, E, D, HPFHHbO Arab/ C, E, D, HPFH HPFH / HPFHHPFH / HPFH

HbH / HbH / Thalassemia !Thalassemia ! Thalassemia major/Thalassemia major/αα+/º +/º

Thalassemia! Thalassemia! Thalassemia major / HbC, DThalassemia major / HbC, D

serious serious anemiaanemia

HbH / HbH / αα+/º +/º ThalassemiaThalassemia HbS / HbS / Thalassemia Thalassemia HbS / HbCHbS / HbC HbS / HbDHbS / HbD HbS / HbEHbS / HbE HbS / O ArabHbS / O Arab

Prenatal Diagnosis Prenatal Diagnosis (PND)(PND)

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