Sickle cell disease clinical phenotypes in Nigeria: A preliminary analysis of the Sickle Pan Africa Research Consortium Nigeria database.

BACKGROUND/OBJECTIVE: Sickle cell disease (SCD) is a monogenic disease with multiple phenotypic expressions. Previous studies describing SCD clinical phenotypes in Nigeria were localized, with limited data, hence the need to understand how SCD varies across Nigeria. METHOD: The Sickle Pan African Research Consortium (SPARCO) with a hub in Tanzania and collaborative sites in Tanzania, Ghana and Nigeria, is establishing a single patient-consented electronic database with a target of 13,000 SCD patients. In collaboration with the Sickle Cell Support Society of Nigeria, 20 hospitals, with paediatric and adult SCD clinics, are participating in patient recruitment. Demographic and clinical information, collected with uniform case report forms, were entered into Excel spreadsheets and uploaded into Research Electronic Data Capture software by trained data clerks and frequency tables generated. RESULT: Data were available on 3622 patients enrolled in the database, comprising 1889 (52.9%) females and 1434 (39.6%) children ≤15 years. The frequencies of Hb SS, Hb SC and Hb Sß thalassemia in this data set were 97.5%, 2.5% and 0% respectively. Sixty percent, 23.8%, 5.9%, 4.8% and 2.5% have had bone pain crisis, dactylitis, acute chest syndrome, priapism and stroke respectively. The most frequent chronic complications were: leg ulcers (6.5%), avascular necrosis of bone (6.0%), renal (6.3%) and pulmonary hypertension (1.1%). Only 13.2% had been hospitalized while 67.5% had received blood transfusion. CONCLUSION: These data on the spectrum of clinical phenotypes of SCD are useful for planning, improving the management of SCD across Nigeria and provide a foundation for genomic research on SCD.

Pattern of haemoglobin phenotypes in newborn infants at the national hospital abuja using high performance liquid chromatography.

BACKGROUND: Haemoglobin (Hb) disorders are among the most common blood genetic disorders worldwide, and they constitute an important cause of morbidity and mortality, especially in Nigeria. Despite the clinical significance of early diagnosis, newborn screening for these conditions is not routinely done in Nigeria. OBJECTIVE: This study was undertaken to document the pattern of Hb phenotypes of newborn babies at the National Hospital Abuja and highlight the relevance of neonatal screening for early diagnosis of abnormal Hb phenotypes in Nigeria. SUBJECTS AND METHODS: A prospective study of eligible newborn babies delivered in the hospital at the study site was undertaken following parental informed consent. Venous blood was collected from the babies into an ethylenediaminetetraacetic acid sample bottles. The samples were analysed using high-performance liquid chromatography (HPLC) techniques, and the Hb phenotypes obtained were documented. Data were analysed using the Statistical Package for Social Sciences (SPSS) version 20 (IBM-SPSS, Armonk, NY, USA). RESULTS: Three hundred and eleven newborns (male = 173, female = 138) aged 0-28 days were recruited. Two hundred and thirty-six (75.9%) babies had Hb AA (FA) phenotype, 63 (20.3%) Hb AS (FAS), 6 (1.9%) Hb SS (FS), 4 (1.3%) Hb AC (FAC) and 2 (0.6%) had abnormal HbA variants. The overall prevalence of abnormal Hb phenotype was 24.1%. The results showed a significant association of sex (P = 0.003) and ethnicity (P = 0.047) with Hb phenotype. CONCLUSION: There is a wide spectrum of abnormal Hb phenotypes in Nigeria, and these phenotypes can easily be detected at birth using HPLC. We, therefore, recommend routine neonatal screening for sickle cell disease by HPLC in Nigeria.