Thalassemia autosomal recessive disease

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Transcript of Thalassemia autosomal recessive disease

ThalassemiaPrepared by :Christian RavinaM.sc.NursingChild Health Nursing department 2nd year, 4th semM.T.I.N.Changa

Introduction

• Thalassemia is a hereditary hemolytic disorder occurring predominanentlyin persons of mediterraneanor asian origin.

• Thalassemia = thalassa -great sea

• The disease first described by Cooley in 1925.

Introduction

• It was first noticed in patients originating from the littoral (દરિયાઈ)countries of Mediterranean sea.

• The prevalence of the disease in India high among Gujaratis, Sindhis , Punjabis

• Thalassemia major is known as Cooley’s anemia or mediterranean anemia .

Definition

• Thalassemia is a group of hereditary anemia characterized by reduction in the synthesis of hemoglobin.

• It produce hypochromic microcytic anemia due to defective hemoglobinization of RBCS, Hemolysis & ineffective erythropoiesis .

• It can be considered as hemolytic & hypoproliferativeanemia related to abnormal hb.

Causes

• Thalassemia is caused by mutations in the DNA of cells that make hemoglobin — the substance in your red blood cells that carries oxygen throughout your body. The mutations associated with thalassemia are passed from parents to children.

• Alpha chain synthesis is reduced due to gene deletion which reduces the level of all 3 normal hemoglobin A, A2,F & causing alpha – Thalassemia .

• Beta Thalassemia is usually caused by point mutations rather than large deletions.

• Delta –beta Thalassemia is due to suppression of both beta & delta chain synthesis with moderate anemia & high hbF.

Classification

Signs and Symptoms

• Major : manifested at age 3 months with progressive pallor, jaundice, hepatosplenomegaly , recurrent respiratory infection , enlargement of lymph nodes & growth failure .

• Severe cases facial appearance become mongoloid & bossing of skull , prominent frontal & parietal eminences with flat vault & straight forehead .

Signs and symptoms • Maxilla becomes prominent with exposure of

malformed teeth . Bridge of nose become depressed with puffy eyes .

• Anorexia

• poor feeding

• Abdominal Distension

• Irregular fever

• Infection

• Increase pigmentation of skin found bronze discolouration

• Hypogonadism,

Diagnostic evaluation

• Laboratory diagnosis:

• Thalassemia minor:

-Blood smear shows hypochromia and microcytosis (similar to Iron Deficiency Anemia).

-Blood indices: MCV< 75 fl, Hb usually> 10, Hematocrit> 30%, RDW < 14%.

-Hemoglobin A2 often elevated > 3%, sometimes reaching 7-8%.

• Thalassemia major:

-Blood smear shows profound microcytic anemia, with extreme hypochromia, tear drop, target cells and nucleated RBCs.

-Hemoglobin may be very low at 3-4 g/dl.

Prenatal diagnosis

• Early prenatal diagnosis can be done using first fetal blood sampling, and later chorionvillus biopsy and direct analysis of the globin genes.

• The error rate in experienced centers is now well under 1%.

Management and treatment

• Repeated blood transfusion

• Iron chelation

• Splenectomy

• Folic acid supplementions

• Bone marrow transplantation

Management and treatment

•Thalassemia minor (trait) :•No need for any treatment, since the

carriers are usually symptomless.

Management and treatment

• Thalassemia major:

• The severe life-threatening anemia, requires regular life long blood transfusion, to compensate for damaged red blood cells.

• The continuous blood transfusion will eventually lead to iron overload, which must be treated with chelation therapy to avoid organ failure.

• Other novel treatments like bone-marrow transplantation are very costly.

• New treatments includes the use of oral chelators, to replace the chelation treatment using Desferal delivered by infusion under the skin through a battery-operated pump.

• Gene therapy is also an option still researched

Repeated blood transfusion • Regular interval to maintain Hb level

at least 10-11 gm/dl.

• Interval and amount depends upon the child.

• Usually 10-15 ml/kg every 2-3 weeks washed packed RBCs are transfused.

• Special precautions to prevent complication.

• If donated RBCs are pretreated with sodium chloride, adenine, glucose and mannitol they survive longer period in receipients body.

Iron chelation therapy

• Chelation therapy is the administration of chelating agents to remove iron from the body.

• Desferrioxamine(Desferal ): To prevent complication of repeated blood transfusion i.e. hemosiderosis & hemochromatosis .

• SQ infusion dose 25 to 50 mg/kg /day over 8 to 12 hours through micro-infusion pumps.

• Usually this therapy is given at night & 5 to 6 nights per week.

• It is given after 10-15th transfusion .

• Serum ferritin level is maintained between1000-2000ng/ml

• Vitamin ‘C’ 100 mg/day is given concurrently to enhance iron excretion.

• Overdose of iron chelating agent may result in growth retardation, visual problem & hearing toxicity.

• Oral iron chelating agent (Desfereprone) Dose 75 to 100 mg/kg/day in 2-3 divided in dose, Side effect : joint pain, vomiting , pain in abdomen .

Splenectomy

•Spenectomy is indicated when child need very frequent blood transfusion and child develop hypersplenismor big spleen causing discomfort.

Folic acid supplementations

•Folic acid supplementations are recommended whereas iron therapy and dietary iron should be avoided to prevent more iron deposition.

Supportive management

• To manage associated problems and treat complications

• Vaccination with hepatitis “B” to be given to prevent transfusion related infection along with other routine immunization.

• Emotional support

Bone marrow transplantation

• Bone marrow transplantation is a effective treatment modality with potential of curing thalassemia.

• Defective stem cell are replaced by normal stem cell.

• It is extremely expensive and possible in only very selective cases.

New approaches

• New approaches in the management of thalassemia are gene therapy and gene manipulation.

• In gene therapy, insertion of normal gene is done in the stem cells to correct underlying defect.

• It is done in two approaches, i.e. somatic and transgenic.

• In gene manipulation, excess of alpha chains is decreased by increasing the gamma chains.

Prevention efforts

• Pre marital screening to make sure that the couple are not both carriers.

• Provision of counseling and health education for the thalassemics, their families and the public .

• Provision of prenatal testing for thalassemia.

• Reduction of marriages between relatives( consanguineous).

Nursing management

• Promote compliance with transfusions and chelation therapy

• Assist the child and family to cope with anxiety producing illness and its treatments

• Observe for complication of multiple transfusion

• Prevent and treat infections

• Promote normal or near normal growth and development

• Encourage activities of daily living according to tolerance