The effectiveness and barrier of reverse cascade screening for paediatric familial hypercholesterolaemia
Authors: Tani R , Matsunaga K , Inoue T , Fu H , Ishizawa M , Ishikawa K , Murakami K , Noma T , Nishioka K , Irie K , Kondo S , Iwase T , Kusaka T , Minamino T 
Published: October 2024

Abstract

Background
Familial Hypercholesterolaemia (FH) is an autosomal dominant genetic disorder that is prevalent in one out of every 300 individuals in the general population. Recognized as an actionable condition, early diagnosis of FH in children is crucial to prevent the onset of atherosclerosis, and equally important is the identification of parents before the development of coronary artery disease events. Therefore, the significance of universal FH screening during childhood combined with reverse cascade screening has been increasingly acknowledged. To achieve these objectives, in our region, universal lipid screening is conducted in elementary schools for children aged 9 or 10 years, annually screening approximately 8,000 individuals, with those identified being referred through a three-step process to four major healthcare facilities within the prefecture. However, the effectiveness of reverse-cascade screening remains unclear.

Purpose
Our study aimed to assess the effectiveness of and identify barriers to implementing reverse cascade screening in conjunction with universal lipid screening.

Methods
We conducted a single-center, retrospective observational study from January 2018 to July 2023 and evaluated the utility of reverse cascade screening for children genetically diagnosed with FH following universal screening. This study analysed prevalent barriers and identified families with suspected FH through reverse cascade screening, counting those with Potential FH among second-degree relatives. Beyond successful identification, we categorized the frequently encountered barriers into five distinct categories: bereavement, prior cardiovascular events, dyslipidaemia with unspecified LDL-C levels, incomplete family history information, and inadequate disease awareness of FH. Reverse FH diagnosis adhered to current guidelines.

Results and Discussion
Of 151 paediatric patients referred to our facility, 67 were genotypically confirmed to have FH. Excluding 8 cases of divorce and 4 cases of tracking challenges, 55 patients were finally analysed. 62 patients were diagnosed with reverse FH, and appropriate treatment was initiated. Notably, 158 cases of Potential FH were identified. (25 first-degree and 133 second-degree relatives). While a higher number of reverse FH diagnoses were observed in first-degree relatives (55 cases), the diagnostic yield was lower among second-degree relatives (seven cases). Common barriers for second-degree relatives included dyslipidaemia with unspecified LDL-C levels (42 cases) and incomplete family history information (66 cases).

Conclusion
Integrating universal screening with reverse cascade screening facilitates the identification of new FH cases. A comprehensive strategy for diagnosing reverse FH is paramount, raising disease awareness, genetic testing, the development of a family-based care plan, and enhancing access to information and communication technologies.