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Sensitization & Awareness
1 Sensitization of medical and school communities by meetings of all relevant groups
including PTA, principals, school nurses, guidance counselors.
2 Circulating information to parents requesting written refusal for non-participation.
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3 Illustrated lectures on sickle cell disease, genetics and its prevention.
4 Logistics of screening process.
Obtain 4th form class lists and generate preprinted labels.
Students complete data forms providing demographic information, date of birth, class, etc. Screening sessions arranged and staffed by team of 3 experienced phlebotomists
Good organization screens 100 students/hour or 150-170 students in 2 hours.
Schools with < 200 students require 2 visits; larger schools receive up to 4 visits.
5 Blood samples are taken in the school environment.
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6 Samples are analysed in dedicated laboratory in the Southern Regional Health Authority.
7 Permanent genotype cards are produced with counselling of carriers.
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| Sample Collection and Coverage |
| 2007/8 |
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| 2008/9 |
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| *screened previously refers to schools with 6th forms and that students had already been screened in the 5th form of the same or other schools. |
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| Laboratory Analysis |
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| Samples are sorted against a computerized database and ID numbers allocated. |
An automated haematology analyser gives red cell indices. An MCH ≤ 26pg suggests beta thalassaemia trait. |
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| Alkaline haemoglobin electrophoresis detects HbS, HbC, and other variants. |
The slide sickle test confirms the identity of HbS |
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| Beta thalassaemia trait is suspected with an MCH ≤ 26pg and an RDW < 18, supported by HbA2 values ≥ 3.5% on HPLC (above) and confirmed by molecular studies. |
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| Results of School Screening |
| a) Haemoglobin Genotypes |
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A rare haemoglobin variant of either the alpha or beta chain – usually harmless.
Aßth - beta thalassaemia trait
HPFH - hereditary persistence of fetal haemoglobin trait (a harmless condition)
Sßoth - sickle cell-ßo thalassaemia (a potentially serious form of sickle cell disease)
Sß+th - sickle cell-ß+ thalassaemia (a mild form of sickle cell disease)
SHPFH - sickle cell-hereditary persistence of fetal haemoglobin (a harmless condition)
CC - homozygous HbC disease or HbC-ßo thalassaemia (a mild condition with slight anaemia)
Var. - a rare haemoglobin variant of either the alpha or beta globin chain.
b) Molecular mutations
Beta thalassaemia mutations
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| -29 A→G |
9 (African gene) |
| -88 C→T |
13 (African gene) |
| IVS1-5 G→A |
2 (African gene) |
| IVS1-108 T→C |
2 (Mediterranean gene) |
| IVS1-110 G→A |
2 (Mediterranean gene) |
| IVS2-849 A→G |
1 (African gene) |
| PolyA T→C |
1 (African gene) |
| Total |
30 |
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Data courtesy of Prof. Andreas Kulozik, University of Heidelburg , Germany .
Rare haemoglobin Variants
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| Alpha chain |
HbG Philadelphia 1 |
Beta chain
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Hb Copenhagen 1 |
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Hb Caribbean 1 |
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Data courtesy of Prof. Douglas Higgs and Dr. Chris Fisher, University of Oxford , UK .
Hereditary Persistence of Fetal Haemoglobin (HPFH)
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HPFH-1 (Black HPFH)
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6 |
HPFH-2 (Ghanaian HPFH)
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7 |
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These are rare variant genes estimated to occur 1 in every 5,000 Afro-Americans, In Manchester, these 13 genes occurred in 4,758 students or 1 in 366 so it appears to be
14 times more frequent than estimates from the US .
Data courtesy of Dr. Abdullah Kutlar and Dr. Niren Patel, Medical College of Augusta , Georgia , US.
c) Findings of Anaemia:
1 Anaemia defined as a haemoglobin < 10g/dl occurred in
- 0.24% males and 3.13% females in 2007/8
- 0.26% males and 3.74% females in 2008/9.
2 This relatively high prevalence in students aged 16-18 years was unexpected and levels were as low as 4.5 g/dl.
3 Virtually all anaemias had the haematological features of iron deficiency with mean cell volumes (MCV) below 75fl, mean cell haemoglobin (MCH) below 28pg, and a red cell distribution width (RDW) above 18.
4 Clinically, the affected students were often tired, short of breath on exertion, manifested pica (eating of ice, dirt, charcoal, chalk, etc.), and many had heavy periods.
5 The predominance among females suggests that heavy periods aggravated the anaemia.
6 There was generally an excellent response to iron therapy in students compliant with therapy and dietary advice.
7 There was a paucity of availability of iron therapy or of educational literature on iron deficiency through the Government health care system which needs to be addressed.
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d) Click here for Prevalence of Anaemia
e) Click here for Response to iron therapy |2007/8| 2008/9
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