1 Logistics |
a) Newborn detection of sickle cell disease is ideal for management since it allows prevention and treatment of many early and serious complications.
b) For the Manchester Project, it also serves the purpose of monitoring any decline in frequency of affected births as a result of the Project’s intervention of genotype detection and counselling of teenagers (referred to as ‘informed cohort’).
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2 Implementation |
Although the informed cohort were attending schools throughout Manchester parish and adjacent Clarendon, some may have moved throughout Jamaica after leaving school. On the assumption that most remain in the area, new born screening has been introduced for Manchester and the adjacent parishes of Clarendon and St. Elizabeth. The distribution of hospitals and estimated annual deliveries are shown below. |
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- Mandeville Regional Hospital – screening began August 2008.
- Hargreaves Memorial & Percy Junor Hospitals; screening began Jan 1, 2009.
- May Pen & Black River Hospitals; screening began January 1, 2010.
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3 Sample Collection
i) Sample Collection - clinical
Samples taken from the umbilical cord following delivery are collected as dried blood spots on ‘Guthrie cards’. These blood spots are stable and carried in batches to the central laboratory in Mandeville.
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ii) Sample Collection - compliance
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4 Sample Analysis |
High levels of fetal haemoglobin (HbF) at birth complicate genotype identification.
Diagnostic method used: August-November 2008 - agar gel
November 2008-present - high pressure liquid chromatography (HPLC). |
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Bio-Rad Variant (HPLC) with tracings of four genotypes |
Confirmation of Abnormal Genotypes |
It is essential to retest the baby by heel-prick at 4-6 weeks to confirm the diagnosis; blood tests in both parents at that time provides useful confirmatory data. Abnormal haemoglobins such as HbS, HbC and other rare variants are readily detected by HPLC but this technology does not detect the genes for beta thalassaemia or HPFH although these will be shown by tests on the parents. |
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5 Results |
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