Homozygous familial hypercholesterolemia in China: Genetic and clinical characteristics from a real-world, multi-center, cohort study.

BACKGROUND

There is a lack of large-scale data on the clinical and genotype characteristics of homozygous familial hypercholesterolemia (HoFH) patients in Asia.

OBJECTIVE

To define the characteristics of phenotypic and genetic HoFH probands from mainland China.

METHODS

We collected data from patients with suspected HoFH from ten clinical hospitals across mainland China from 2003 to 2019. Clinical data and DNA testing were obtained in all patients. The Kaplan-Meier method was used to generate survival curves, and the groups were compared with the log-rank test.

RESULTS

A total of 108 unrelated probands with suspected HoFH (mean age 14.9 years) were included. The three most common variants were W483X (c.1448 G>A), A627T (c.1879 G>A), H583Y (c.1747 C>T). The majority (64.8%) were compound heterozygotes (n = 70), 23 (21.3%) were true HoFH patients. True HoFH showed higher LDL-C levels compared to compound HoFH (16.8±3.6 mmol/L vs. 15.0±3.1 mmol/L, P = 0.022). During follow-up, only 21.2% patients exhibited an LDL-C reduction of more than 50%. Kaplan-Meier analysis showed that the true HoFH probands had significantly worse survival rates compared to other genotype probands (13-year survival; 20.3% vs. 76.7%, respectively; P = 0.016). In addition, true HoFH shows that 2.8-fold (P = 0.022) increase any death and 3.0-fold (P = 0.023) increase cardiovascular death risk in relative to other FH.

CONCLUSIONS

This report shows that HoFH has devastating consequences, and that patients are often only diagnosed after they have been exposed to severely elevated LDL-C for years. Systematic screening and early intensive treatment are an absolute requirement for these young individuals with HoFH.