Genetic Spectrum of Familial Hypercholesterolaemia in the Malaysian Community: Identification of Pathogenic Gene Variants Using Targeted Next-Generation Sequencing.

Familial hypercholesterolaemia (FH) is caused by mutations in lipid metabolism genes, predominantly in low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), proprotein convertase subtilisin/kexin-type 9 (PCSK9) and LDL receptor adaptor protein 1 (LDLRAP1). The prevalence of genetically confirmed FH and the detection rate of pathogenic variants (PV) amongst clinically diagnosed patients is not well established. Targeted next-generation sequencing of LDLR, APOB, PCSK9 and LDLRAP1 was performed on 372 clinically diagnosed Malaysian FH subjects. Out of 361 variants identified, 40 of them were PV (18 = LDLR, 15 = APOB, 5 = PCSK9 and 2 = LDLRAP1). The majority of the PV were LDLR and APOB, where the frequency of both PV were almost similar. About 39% of clinically diagnosed FH have PV in PCSK9 alone and two novel variants of PCSK9 were identified in this study, which have not been described in Malaysia and globally. The prevalence of genetically confirmed potential FH in the community was 1:427, with a detection rate of PV at 0.2% (12/5130). About one-fourth of clinically diagnosed FH in the Malaysian community can be genetically confirmed. The detection rate of genetic confirmation is similar between potential and possible FH groups, suggesting a need for genetic confirmation in index cases from both groups. Clinical and genetic confirmation of FH index cases in the community may enhance the early detection of affected family members through family cascade screening.

Undertreatment and Underachievement of LDL-C Target among Individuals with High and Very High Cardiovascular Risk in the Malaysian Community.

Dyslipidaemia is a major cause of morbidity and mortality. The aims of this study are to determine the prevalence of dyslipidaemia subtypes, the proportions of lipid-lowering therapy (LLT) use, and the achievement of low-density lipoprotein cholesterol (LDL-C) treatment targets for high-risk (HR) and very high-risk (VHR) Malaysians. This cross-sectional study involves 5279 participants across 11 states in Malaysia. The data were obtained through a standardised questionnaire, anthropometric measurements, venous glucose and lipid profile. The participants with existing cardiovascular disease (CVD) or diabetes with at least one of the other major risk factors (smoking, hypertension or dyslipidaemia) were grouped into the VHR category. Other participants were risk-categorised using the Framingham General CVD Risk Score (FRS-CVD). The prevalence of elevated LDL-C, LLT use and LDL-C target were set according to respective risk categories. Pearson's chi-squared test was used to test the difference in the proportions. The mean ± standard deviation (SD) age was 41.1 ± 14.8 years, and 62.2% (3283/5279) of the group were females. Within the participant group, 51.5% were found to have elevated total cholesterol, 28.8% had low HDL-C, and 33.8% had high triglyceride. As for elevated LDL-C, 9.8% were in VHR, 8.6% in HR, 5.8% in MR and 34.9% in LR categories. Among the VHR group, 75.8% were not on LLT, and only 15.9% achieved the LDL-C target. As for the HR category, 87.7% were not on LLT, and only 16.1% achieved the LDL-C target. Dyslipidaemia is highly prevalent among Malaysians. The majority of VHR and HR participants were not on LLT and did not achieve LDL-C treatment targets. Proactive programs are warranted to combat dyslipidaemia-associated CVD events in these groups.

Familial Hypercholesterolaemia in the Malaysian Community: Prevalence, Under-Detection and Under-Treatment.

AIM: Familial hypercholesterolaemia (FH) is the most common autosomal dominant lipid disorder, leading to severe hypercholesterolaemia. Early detection and treatment with lipid-lowering medications may reduce the risk of premature coronary artery disease in FH patients. However, there is scarcity of data on FH prevalence, detection rate, treatment and control with lipid-lowering therapy in the Malaysian community. METHODS: Community participants (n=5130) were recruited from all states in Malaysia. Blood samples were collected for lipid profiles and glucose analyses. Personal and family medical histories were collected by means of assisted questionnaire. Physical examination for tendon xanthomata and premature corneal arcus were conducted on-site. FH were clinically screened using Dutch Lipid Clinic Network Criteria. RESULTS: Out of 5130 recruited community participants, 55 patients were clinically categorised as potential (Definite and Probable) FH, making the prevalence FH among the community as 1:100. Based on current total population of Malaysia (32 million), the estimated number of FH patients in Malaysia is 320,000, while the detection rates are estimated as 0.5%. Lipid-lowering medications were prescribed to 54.5% and 30.5% of potential and possible FH patients, respectively, but none of them achieved the therapeutic LDL-c target. CONCLUSION: Clinically diagnosed FH prevalence in Malaysian population is much higher than most of the populations in the world. At community level, FH patients are clinically under-detected, with majority of them not achieving target LDL-c level for high-risk patients. Therefore, public health measures are warranted for early detection and treatment, to enhance opportunities for premature CAD prevention.