HEMA LEC - Hgbopathy Flashcards
Group of inherited disorders causing structurally abnormal globin chain synthesis due to AA substitutions
HEMOGLOBINOPATHIES
HEMOGLOBINOPATHIES are hetero or homozygous disease?
• Homozygous disease conditions (both globin chains affected)
what cells are associated with Hgbopathy
Target cells and sickle cells
HEMOGLOBINOPATHY DIAGNOSIS [3]
- Hgb electrophoresis
- Isoelectric focusing
- DNA (PCR) Analysis
When valine replaces glutamic acid at position 6 on both beta chains
Hgb SS
Hgb SS Inherited from one or both parents?
• Inherited from both parents
percentage of HbA produced if w/ Hgb SS
0%
percentage of HbS produced if w/ Hgb SS
80%
percentage of HbF produced if w/ Hgb SS
20%
Hb insolubility results when _______ is formed
deoxyhemoglobin
Hgb ___ Clinical Findings
• Tissue necrosis
Hgb SS
Hgb ___ Clinical Findings
All organs are affected; with kidney failure being a common outcome; hyposplenism and joint swelling also occur
Hgb SS
Hgb ___ Clinical Findings
Diagnosis is made after 6 months of age (time of beta-gamma globin chain switch), with life expectancy of 50 years with proper treatment
Hgb SS
(time of beta-gamma globin chain switch)
6 months of age
Hgb ___ Clinical Findings
Death usually results from infection or congestive heart failure.
Hgb SS
Inclusion bodies found in Hb SS [2]
Pappenheimer bodies
H-J Bodies
Hgb S migrates with Hemoglobins ? and ? on alkaline hemoglobin electrophoresis; can differentiate using acid electrophoresis
D & G
Hgb SS Laboratory Findings Blood picture
bone marrow erythroid hyperplasia (M:E ratio decreases)
Severe normocytic/normochromic hemolytic anemia with polychromasia resulting from premature release of reticulocytes
Hgb SS Laboratory Findings
M:E Ratio effect
bone marrow erythroid hyperplasia (M:E ratio decreases)
cells present in Hgb SS [3]
Sickle cells, target cells, nucRBCs,
Hb __ lab findings
Increased bilirubin and decreased haptoglobin due to hemolysis
Hb SS
When valine replaces glutamic acid at position 6 on ONE beta chains
Hgb AS
one normal beta chain can produce some Hgb A
Hgb AS
Percentage of Hgb A in Hgb AS
60%
Percentage of Hgb S in Hgb AS
40%
generally produces no clinical symptoms. anemia is rare, but if present, will be normo/normo and sickling can occur during rare crisis states
Hgb AS
when lysine replaces glutamic acid at position 6 on both beta chains
Hgb CC
Percentage of Hgb A in Hgb CC
0%
Percentage of Hgb A2 in Hgb CC
2
Percentage of Hgb F in Hgb CC
7
Percentage of Hgb Cin Hgb CC
90%
Normo/normo anemia with target cells, intracellular rodlike crystals
Hgb CC
Hb C migrates with Hgb
A2, E, O
The ___ Hgb C trait patient is asymptomatic, with no anemia, one normal beta chain is able to produce 60% Hb A, 40% Hb C, normal amounts of A2 and F
HETEROZYGOUS
double heterozygous condition where an abnormal sickle gene from one parent and an abnormal C gene from the other parent is inherited
Hgb SC
percentage of Hb A in Hgb SC
0%
percentage of Hb S in Hgb SC
50%
percentage of Hb C in Hgb SC
50%
percentage of Hb F in Hgb SC
7%
moderate to severe normo/normo with target cells, characterized by SC crystals, may see rare sickle cells or C crystals
Hgb SC
when lysine replaces glutamic acid at position 26 on the beta chain
Hgb E
homozygous condition results in mild anemia with microcytes and target cells; heterozygotes are asymptomatic
Hgb E
when glycine replaces glutamic acid at position 121 on the beta chain
Hgb D
abnormal Hgb variants
HbM: alpha 2 (58th His to Tyr), beta 2
Hgb M
tetramer of gamma
Hb Bart
abnormal variant of Hb F
Hb Bart
Decrease Hb insolubility
Hgb SS
Immunity to falciparum (2)
Hgb SS
Hgb AS
+ Hgb Solubility Screening Test
3
Hgb SS
Hgb AS
Hgb SC
No Hgb A produced (2)
Hgb SS
Hgb CC
Asymptomatic
AS
Heterozygous Hb C
Heterozygous Hb E
- Occurs most commonly in African-American, African, Mediterranean, and Middle East populations.
Sickle Cells Disease (Hgb SS)
is the most common hemoglobinopathy in the United States.
heterozygous trait
- Occurs in the African-American And African populations.
Hgb C Disease / Hgb CC
African, Mediterranean, and Middle Eastern populations
Hgb SC Disease
