Understanding Ethnic Health Inequalities in the Genetic Testing and Diagnosis of Familial Hypercholesterolemia

Ongoing

Background 

Familial hypercholesterolemia (FH) is a common monogenic disorder of lipoprotein metabolism associated with high concentrations of low-density lipoprotein cholesterol (LDL-C) in the blood, predisposing affected individuals and their families to premature coronary heart disease if untreated. In the UK, approximately 1 in 250 people are affected by this condition, suggesting there could be up to 220,000 affected individuals in Britain, of whom less than 8% are currently identified. 

FH has an autosomal dominant mode of inheritance, meaning children and siblings of a person with FH have a 50% chance of inheriting this condition. Those individuals who only inherit one ‘defective’ gene from their parents are heterozygous for the disorder. Therefore, a GP practice with 10,000 registered patients could have about 20 patients with familial hypercholesterolaemia, clustered in six to eight families. Despite advances in clinical practice and research, a substantial gap remains in the understanding of the unique burden of FH among non-White individuals globally.  

 Why this work is important

There is currently limited knowledge regarding the burden of FH and disparities in research and care for Black, Asian and minority ethnic individuals and their families with limited genetic, clinical, and population-level studies conducted to contribute to this understanding. The lack of data disaggregated by ethnicity and clinical risk hampers our understanding of ethnic differences in FH outcomes. Though national guidelines recommend early identification, an estimated 80% of heterozygote FH still remain undiagnosed. It is imperative that those individuals with FH have access to genetic testing, family cascade screening, as well as prompt treatment with high-intensity lipid-lowering therapies. However, there is evidence that disparities remain in the diagnosis and subsequent treatment of FH in ethnic minorities. Data from the US has demonstrated that Black people were diagnosed with FH at older ages than any other race/ethnicity. Furthermore, persons with FH from Asian and Black backgrounds were roughly 50% less likely than White people to achieve their treatment goals. Further research is needed to understand how these disparities are reflected in the UK population.  

The 2019 NHS Long Term Plan set the ambitious target of finding 25% of the predicted FH patients in England in the next 5 years. There are a number of approaches to identification of affected individuals. These methods include Dutch Lipid Clinic Criteria, Simon Broome Criteria8 and assessment using the familial hypercholesterolaemia case ascertainment identification tool (FAMCAT) methods. However, it is important to determine whether these screening tools are able to adequately detect FH in ethnic minority groups.  

Aim  

Using intersectional and life course frameworks, we will examine the current identification of FH within and across  ethnic groups, impact of proactive identifications of FH in primary care on these groups and the subsequent clinical care pathway.  

The study will consist of 2 Work Packages which will run concurrently to allow integration of qualitative and quantitative approaches throughout the study, so our findings will not be driven by theory or data exclusively – and allow a process of moving back and forth between induction and deduction to synthesise our findings. 

Project outputs  

  1. Updating our previous review on ethnic disparities in diagnosis and treatment of FH 
  2. Mixed methods research: 2-3 papers focusing on: 
  3. intersectional analyses to understand ethnic disparities in FH,  
  4. quantitative and qualitative aspects of case finding including diagnosis, referral, testing, treatment and evaluation of care pathways, considering biases due to structural and institutional racism 
  5. Final report 
  6. Evidence-based and co-designed targeted and actionable recommendations 

Timelines  

The report is due to be published in Autumn 2024  

Further information 

For further information please contact Dr Veline L’esperance (Senior Clinical Advisor) at info@nhsrho.org