Rapid Screening and Etiological Stratification of Inherited Dyslipidemias by Infrared Microspectroscopy

Abstract Inherited dyslipidemias, including familial hypercholesterolemia (FH) and sitosterolemia (STSL), present overlapping clinical manifestations but require distinct therapeutic interventions. Current diagnosis relies on genetic sequencing and mass spectrometry-based sterol profiling, which are accurate but costly, time-consuming, and unsuitable for large-scale first-line screening. Infrared (IR) microspectroscopy offers a rapid, label-free alternative for biochemical phenotyping; however, its clinical application is challenged by the spatial heterogeneity of biological samples and spectral variability. Here, we present an IR microspectroscopic phenotyping framework for rapid screening and etiological stratification of inherited dyslipidemias. The framework combines multi-pixel IR microspectroscopy, batch-effect correction, and participant-level spectral integration to achieve reproducible cross-batch phenotyping while preserving disease-associated biochemical signatures. Quantitative models predicted FH-associated lipid biomarkers, whereas qualitative classifiers identified STSL-associated sterol biomarkers. A cascade decision framework integrating IR-based phenotypic classification with biomarker profiling further enabled etiological discrimination among healthy controls, FH, and STSL. The framework achieved an average participant-level sensitivity of approximately 93% and yielded detection rates of 97.7% for FH and 85.7% for STSL, compared with 93.2% and 60.7%, respectively, with conventional clinical screening. Co-importance and consensus feature analyses identified 2837 cm−1 as a prominent discriminatory spectral feature. Measurements of β-sitosterol reference standards revealed a characteristic absorption band near 2834 cm−1, supporting a possible association between this spectral region and β-sitosterol-related biochemical variation. This internally validated proof-of-concept study supports the potential of IR microspectroscopy for rapid etiological stratification of inherited dyslipidemias, complementing genetic sequencing and mass spectrometry.