Skip to main content

Haematology summray 7


Chapter 7 in Haematology (Genetic disorder of haemoglobin) summary

 

-Genetic disorders of haemoglobin fall into two main groups:

1-The thalassaemias in which synthesis of the alpha or beta globin chain is reduced.

2-Structural disorders in which an abnormal haemoglobin is produced.

-The alpha or beta thalassaemias occur clinically as minor forms with microcytic hypochromic red cells and a raised red cell count with or without anaemia.total absece of function of all four alpha globin genes causes hydrops fetalis.

-Total absencce of function of both beta globin genes causes beta thalassaemia major , a transfusion –dependent anaemia associated with iron overload. Thalassaemia intermedia is a clinical term for a group of disorder showing mild to moderate anaemia and is usually caused by variants of beta thalassaemia.

-The most frequent structural defect of haemoglobin is the sickle mutation in the beta globin chain causing, in the homozygous form, a sever haemolytic anaemia, associated with vaso-occlusive crises.these may be painful affecting bone or affect soft tissue (e.g.chest,spleen or central nervous system).crises may also be haemolytic or aplastic.

-Antenatal diagnosis using PCR technology to amplify chorionic villous DNA is used to detect sever genetic defect of haemoglobin production,with termination of the pregnancy if appropriate .



  From book: Essentail Haematology A.V.HOFFBRAND,P.A.H.MOSS.6EDITION
Labels:

Comments

Post a Comment

Popular posts from this blog

Heamatology summary 12

Chapter 12 in Haematology (Haematoloical malignancy: managment) summary -Progress in the treatment of haemopoietic malignancies has been the result of improvemnets in both supportive therapy and speicific tumour treatments. -Supportive treatments often include : insertion of a central nevous catheter; Appropriate use of red cell and platelet transfusions; Early administration of drugs to traet infection;Otimiziation of the blood coagulation system Drugs to reduce side effects such as nausea or pain;Psychological support. -Gram-positive skin organisms such as staphyloccus are common infections and often colonize central venous catheters. -Gram-Negative bacteria are usually derived from the gut and and can cause severe septicemia. -The use of air filters,handwashing and antibiotics can reduce infection rates . -Neutropenic patients who developa fever should be treated urgently with broad-spectrum antibiotics. -Herpes viruses are a common cause of infection in ...
Post a Comment
Read more

Haematology summray 8

Chapter 8 in Haematology (Granulocytes and monocytes) summary -Granulocytes include neutrophils (polymorphs),eosinophils and basophils.They are made in the bone marrow under the control of a variety of growth factors   and have a short lifspan in the blood stream befor entring tissues. -Phagocytes (neutrophils and monocytes) are the   body's main defence against bacterial infection.Neutrophil leucocytosis occurs in bacterial infection and in other types of inflammation.Neutropenia , if severe, predisposes to infection. It may be caused by bone marrow failure, chemotherapy or radiotherapy drugs. -Eosinophilia is most frequently caused by allergic diseases, including skin diseases,parasitic infection or drugs. Ti can be caused by clonacal increase in eosinophils termed chronic eosinophil leukamia or an idiopathic condtion, often associted with tissue damage. -Detects of function of neutrophils and monocytes may affect their chemotaxis, phagocytesis oe killing. ...
Post a Comment
Read more

Haematology summray 9

Chapter 9 in Haematology (White cells: lymphocytes) summary -Lymophcytes are immunologically comptent white cells that are involved in antibody production   (B cells) and with the body's defence against viral infection or other foreign invasion (T cells). -They arise from haemopoietic stem cells in the marrow, T cells being subseqently processed in the thymus. -B cells secrete gammaglobulin antibodies specific for individual antigens.T lymphocytes are further subdivided into helper (CD4 + ) and cytotoxic (CD8 + )cells .They recognise peptides on HLA atigens.Natural killer cells are cytoxic CD8 + cells that kill target cells with low expression of HLA molecules. -The immune response occurs in the germinal centre of lymph nodes and involves B-cell and T-cell proliferation, somatic mutation, selection od cells by recognition of antigen on antigen-presenting cells and formation of plasma cells (which secrete immunoglobulin)or memory B cells. -Immunoglobulins inc...
Post a Comment
Read more