Genetic and Haematological Modifiers of SCD Severity in Kaduna State, Northern Nigeria — SCA  

Sickle Cell Disease Clinical Trial

Official title: Assessment of Genetic and Haematological Modifiers of Disease Severity Among Patients With Sickle Cell Disease (SCD) in Kaduna State, Northern Nigeria

Status Not yet recruiting

Clinical Trial Summary

This study is aimed to assess the genetic and haematological modifiers of disease severity among patients with Sickle Cell Disease (SCD) in Kaduna State, northern Nigeria. It is composed by two separate study designs: a cross-sectional study and a longitudinal study.

The cross-sectional study will evaluate clinical and laboratory parameters in paediatric Sickle Cell Anaemia (SCA) patients (ages 2-18 years) in steady state and during Vaso-Occlusive Crisis (VOCs) to determine the parameters that can be used as a guide to monitor the course of the disease towards early recognition and management of sickle cell crises. In addition, the study will explore genotype-phenotype correlations in SCA patients by targeted Next-Generation Sequencing (NGS) of genetic modifiers for haemoglobinopathies.

The longitudinal study will collect clinical and laboratory data over time for a paediatric cohort of SCD patients (9 months old; followed up to 2 years of age) and parental samples will be collected to determine the βS-globin haplotype in family trios. The aim is to determine the temporal relationships among foetal haemoglobin (HbF) levels, haematological parameters and frequency of sickle cell crises in SCD patients in relation to the type of the βS-globin haplotype and the sickle genotype. In addition, samples collected at 24 months of age will also be analysed by NGS to identify genetic modifiers of clinical manifestations and severity of SCA.

Participants from the following centre will be involved: Ahmadu Bello University Teaching Hospital (ABUTH) Zaria. Consent from all the study parents/legally designated representatives as well as assent from minors will be sought. Consent for genetic analyses will be sought as well. Clinical and haematological analyses will be performed at ABUTH while genetic analyses will be performed at the Cyprus Institute of Neurology and Genetics (CING).

Clinical Trial Description

Sickle cell anaemia (SCA) is a multisystem disorder with massive medical, social and financial implications worldwide. It is caused by a single mutation in the β-globin gene (β6 Glu>Val), which leads to the production of abnormal sickle haemoglobin (HbS). Africa is the major origin of the sickle (βS) mutation, which occurs on diverse genetic haplotype backgrounds. SCA has a Mendelian pattern of inheritance (βS gene homozygosity, i.e. HbSS). Although all SCA patients share the same genetic mutation, the disease exhibits wide heterogeneity in clinical expression, which can be explained by both environmental and genetic factors. The environmental factors include infections, trauma, climate (temperature and humidity) and air quality, as well as socioeconomic factors, many of which are controllable. The genetic factors, on the other hand, cannot be controlled. The best-characterized genetic factors include variants in the genes associated with foetal haemoglobin (HbF) production, co-inheritance of alpha-thalassaemia, sickle genotype, and the type of βS-globin haplotype. The role of other potential genetic modifiers is less clear, particularly with regards to sickle cell disease related organ damage (e.g., risk for stroke, haemolysis, and acute chest syndrome.

Understanding the molecular basis of clinical heterogeneity and disease severity for SCA can have direct clinical applications for prognosis via risk stratification of patients, also facilitating the use of personalized, targeted therapeutic interventions. As a turning-point in genomics, the advent of high-throughput sequencing and whole-genome analysis has made it feasible to discover hitherto unsuspected variants that could add to current understanding of genotype-phenotype relationships in SCA. The identification of modifying genetic variants might suggest new prognostic and/or therapeutic targets for investigation towards improved patient management and treatment. ;

Related Conditions & MeSH terms

• Anemia, Sickle Cell
• Sickle Cell Disease

• NCT number: NCT05837871
• Study type: Observational
• Source: Ahmadu Bello University Teaching Hospital
• Contact: Bello Jamoh Yusuf, Dr
• Phone: 08033733152
• Email: bjamoh@yahoo.com
• Status: Not yet recruiting
• Start date: May 1, 2023
• Completion date: June 1, 2025