Familial Hypercholesterolemia in the Arabian Gulf Region: Clinical results of the Gulf FH Registry

Achievement of guideline targets among people with type 2 diabetes with eASCVD and high risk of ASCVD in the UAE: Results of the PACT-MEA-UAE cohort

AIM

The Prevalence of Atherosclerotic Cardiovascular Disease in Patients with Type 2 Diabetes across the Middle East and Africa (PACT-MEA) study compared cardiovascular disease (CVD) risk and 2021 ESC guidelines adherence between UAE and broader MEA region participants for enhanced type 2 diabetes mellitus (T2D) and atherosclerotic cardiovascular disease (ASCVD).

METHODS

A survey of 385 physicians explored clinical decision-making factors. Chart reviews of 3726 participants classified ASCVD risk as per 2021 ESC guidelines and compared T2D target achievement in primary and secondary care centers.

RESULTS

The survey highlighted factors influencing T2D management decisions, with most adhering to international guidelines. Among 542 UAE participants, 62.7 % were at high and 37.1 % at very high risk for ASCVD. Target HbA1c was achieved 45 % UAE vs. 37 % in regionally, BP by 41 % vs. 30 %, LDL by 36 % vs. 30 %, BMI <25 kg/m2 by 20 % vs. 15 %, SGLT2is use by 63 % vs. 37 % and GLP-1RAs use by 22 % vs. 13 %, respectively. No participants met all ESC-recommended targets for T2D.

CONCLUSION

Physicians followed international guidelines, considering patient history, drug efficacy, and HbA1c levels for diabetes and ASCVD risks. In UAE, <50 % of at-risk individuals with T2D met ESC targets. Cardioprotective medication use was higher in UAE.

Clinical reality and challenges with familial hypercholesterolemia patients' management. 2024 results from the Regional Center for Rare Diseases (RCRD) Registry in Poland

BACKGROUND

Despite advancements in early diagnosis and effective medications in last decade, most heterozygous familial hypercholesterolemia (heFH) patients still fail to achieve their low-density lipoprotein cholesterol (LDL-C) goals and remain at residual cardiovascular disease risk. We present recent data from the regional FH registry in Poland, highlighting the challenges and real-life clinical management of FH patients.

METHODS

The registry is held at the Regional Centre for Rare Diseases, founded in 2016, at the 2nd largest, supraregional hospital in Poland, where >80 different rare diseases in patients from all over Poland are diagnosed and treated, including phenotypically or genetically diagnosed FH patients. Our analysis focused on both children and adult FH patients, excluding those treated with inclisiran due to a small sample size (n = 5).

RESULTS

We studied 173 consecutive heFH patients, median age for adult population was 40 years (range: 27-57), of whom 56.14 % were women. Among the population, 82.1 % were adults (n = 142), and 31 were children (17.92 %; median age 9 (8-13), females 58.16 %). Children exhibited lower total cholesterol and triglyceride levels compared to adults, with no significant differences in LDL-C and high-density lipoprotein cholesterol (HDL-C) levels. Molecular diagnosis in the whole population revealed that 76.6 % had an LDL receptor (LDLR) mutation, while 23.4 % had an apolipoprotein B (APOB) mutation. Risk assessment categorized patients into high (70.7 %), very high (22.1 %), and extremely high (7.1 %) risk groups. Triple therapy achieved treatment goals in 61.76 % of adults and 70.97 % of children. At baseline, 36.62 % of adult patients were not using statins. High-intensity statin therapy combined with ezetimibe was initiated for the remaining patients. Only 3.33 % of patients avoided statins due to complete intolerance. Ezetimibe was used in 57.27 % of patients (mostly in combination therapy), and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors were prescribed for 28.17 % FH patients. In adults receiving statin and ezetimibe therapy, median achieved LDL-C was 141 mg/dl (107-184). For triple therapy, median achieved LDL-C was 52.5 mg/dL (32-86.5). Overall median achieved LDL-C in the study population was 99.5 mg/dl (57.5-145.4). PCSK9 inhibitors reduced LDL-C by 165.6 mg/dl. Combination therapy did not significantly alter baseline lipoprotein(a) (Lp(a)) levels (p = 0.134), and PCSK9 inhibitors led to a mean Lp(a) reduction of 18.66 mg/dl (45 % reduction; p = 0.013). Multivariable regression analysis identified key factors for achieving LDL-C targets in FH patients: DLCN total score, DLCN category, ezetimibe use, and PCSK9 inhibitors.

CONCLUSIONS

In Poland, FH patients are often diagnosed too late (usually over 40 years of age), and many still do not reach their LDL-C goals. Combination LLT double or triple therapy significantly increases the likelihood of achieving LDL-C targets - even up to fivefold. Therefore, unrestricted access to PCSK9 inhibitors for all FH patients is crucial, without the current limitations imposed by drug reimbursement programs like B101.

Possible Heterozygous Hypercholesterolemia Among Adults in Basrah, Southern Iraq

Background Familial hypercholesterolemia (FH) is an autosomal dominant disease and is one of the most prevalent genetic disorders. We aimed to determine the prevalence of patients with elevated levels of low-density lipoprotein cholesterol (LDL-C), presumptively indicating possible heterozygous familial hypercholesterolemia (HeFH). Methods Retrospective data analysis was conducted for adult patients aged 18 and above with fasting LDL-C ≥ 190 mg/dL registered in Faiha Specialized Diabetes, Endocrine and Metabolism Center (FDEMC) in Basrah for the period from August 2008 to December 2023. The total number of enrolled individuals was 59,026. Results From the data records of the 59,026 individuals enrolled in the study, it was found that 4,093 (6.9 %) had LDL-C levels ≥190 mg/dL and 361 (0.6 %) had very high total cholesterol according to the Make Early Diagnosis to Prevent Early Death (MEDPED) Criteria. Around 30,527 (51.7 %) were aged 40-59 years, representing the peak age group. Women comprised 34,688 (58.8 %), and 42,310 (71.7 %) had diabetes mellitus. Individuals with obesity comprise 27,375 (48.8 %). Out of the 4,093 patients with LDL-C ≥190 mg/dL, 2,422 (59.2 %) were in the 40-59 years age group, and 2,847 (69.6 %) were women. Diabetes was found in 3,442 (84.1 %) patients and obesity in 1,954 (49.9 %) patients. The average blood pressure was higher in the individuals with LDL-C ≥190 (137/83 versus 134/82 respectively, p < 0.001). Conclusions Being one of the largest studies of its kind in the country, the percentage of individuals who might meet the criteria for having possible HeFH in Basrah (Southern Iraq) should raise awareness about the size of the problem in the country, both to encourage family screening programs and to broaden the need for lipid-lowering therapies. Future studies are needed to have further clarifications about the differences in the prevalence between sexes and age groups. These findings need further confirmation by genetic studies including LDL-receptor mutations.

A novel equation for the estimation of low-density lipoprotein cholesterol in the Saudi Arabian population: a derivation and validation study

Low-density lipoprotein cholesterol (LDL-C) is typically estimated by the Friedewald equation to guide atherosclerotic cardiovascular disease (ASCVD) management despite its flaws. Martin-Hopkins and Sampson-NIH equations were shown to outperform Friedewald's in various populations. Our aim was to derive a novel equation for accurate LDL-C estimation in Saudi Arabians and to compare it to Friedewald, Martin-Hopkins and Sampson-NIH equations. This is a cross-sectional study on 2245 subjects who were allocated to 2 cohorts; a derivation (1) and a validation cohort (2). Cohort 1 was analyzed in a multiple regression model to derive an equation (equationD) for estimating LDL-C. The agreement between the measured (LDL-CDM) and calculated levels was tested by Bland-Altman analysis, and the biases by absolute error values. Validation of the derived equation was carried out across LDL-C and triglyceride (TG)-stratified groups. The mean LDL-CDM was 3.10 ± 1.07 and 3.09 ± 1.06 mmol/L in cohorts 1 and 2, respectively. The derived equation is: LDL-CD = 0.224 + (TC × 0.919) - (HDL-C × 0.904) - (TG × 0.236) - (age × 0.001) - 0.024. In cohort 2, the mean LDL-C (mmol/L) was estimated as 3.09 ± 1.06 by equationD, 2.85 ± 1.12 by Friedewald, 2.95 ± 1.09 by Martin-Hopkins, and 2.93 ± 1.11 by Sampson-NIH equations; statistically significant differences between direct and calculated LDL-C was observed with the later three equations (P < 0.001). Bland-Altman analysis showed the lowest bias (0.001 mmol/L) with equationD as compared to 0.24, 0.15, and 0.17 mmol/L with Friedewald, Martin-Hopkins, and Sampson-NIH equations, respectively. The absolute errors in all guideline-stratified LDL-C categories was the lowest with equationD, which also showed the best classifier of LDL-C according to guidelines. Moreover, equationD predicted LDL-C levels with the lowest error with TG levels up to 5.63 mmol/L. EquationD topped the other equations in estimating LDL-C in Saudi Arabians as it could permit better estimation when LDL-C is < 2.4 mmol/L, in familial hyperlipidemia, and in hypertriglyceridemia, which improves cardiovascular outcomes in high-risk patients. We recommend further research to validate equationD in a larger dataset and in other populations.

Modern approaches to the management of homozygous familial hypercholesterolemia in the Middle East and North Africa

Homozygous familial hypercholesterolaemia (HoFH) is a severe form of FH in which inheritance of two defective or null mutations in genes associated with metabolism of low-density lipoprotein cholesterol (LDL-C) results in extremely high LDL-C, premature atherosclerotic cardiovascular disease (ASCVD) and mortality. Treatment of HoFH comprises a multi-modal approach of statins, ezetimibe, lipoprotein apheresis; and inhibitors of proprotein convertase subtilisin/kexin type, angiopoietin-like protein 3 (ANGPTL3) and microsomal triglyceride transfer protein. These treatments are generally costly, and patients also often require treatment for ASCVD consequent to HoFH. Therefore, in the interests of both economics and preservation of life, disease prevention via genetic screening and counselling is rapidly becoming a key element in the overall management of HoFH. Guidelines are available to assist diagnosis and treatment of HoFH; however, while advancements have been made in the management of the disease, there has been little systematic attention paid to prevention. Additionally, the Middle East/North Africa (MENA) region has a higher prevalence of HoFH than most other regions - chiefly due to consanguinity. This has led to the establishment of regional lipid clinics and awareness programs that have thrown education and awareness of HoFH into sharp focus. Incorporation of principles of prevention, education, awareness, and data from real-world use of existing therapeutics will significantly enhance the effectiveness of future guidelines for the management of HoFH, particularly in the MENA region.

Identification and functional characterization of two rare LDLR stop gain variants (p.C231* and p.R744*) in Saudi familial hypercholesterolemia patients

BACKGROUND

Familial hypercholesterolemia (FH) is a globally underdiagnosed inherited metabolic disorder. Owing to limited published data from Arab world, this study was conducted with the aim of identifying the genetic and molecular basis of FH in highly consanguineous Saudi population.

METHODS

We performed clinical screening, biochemical profiling, whole exome sequencing and variant segregation analysis of two Saudi FH families. Additionally, 500 normolipic individuals were screened to ensure the absence of FH variant in general Saudi population. Functional characterization of FH variants on secondary structure characteristics of RNA and protein molecules was performed using different bioinformatics modelling approaches.

RESULTS

WES analysis identified two independent rare LDLR gene stop gain variants (p.C231* and p.R744*) consistent to the clinical presentation of FH patients from two different families. RNAfold analysis has shown that both variants were predicted to disturb the free energy dynamics of LDLR mRNA molecule and destabilize its folding pattern and function. PSIPRED based structural modelling analysis has suggested that both variants bring drastic changes disturbing the secondary structural elements of LDLR molecule. The p.C231* and p.R744* variants are responsible for partial or no protein product, thus they are class 1 variants causing loss of function (LoF) LDLR variants.

CONCLUSIONS

This study highlights the effectiveness of the WES, sanger sequencing, and computational analysis in expanding FH variant spectrum in culturally distinct populations like Saudi Arabia. Genetic testing of FH patients is very essential in better clinical diagnosis, screening, treatment, and management and prevention of cardiovascular disease burden in the society.

Protein structural insights into a rare PCSK9 gain-of-function variant (R496W) causing familial hypercholesterolemia in a Saudi family: whole exome sequencing and computational analysis

Familial hypercholesterolemia (FH) is a globally underdiagnosed genetic condition associated with premature cardiovascular death. The genetic etiology data on Arab FH patients is scarce. Therefore, this study aimed to identify the genetic basis of FH in a Saudi family using whole exome sequencing (WES) and multidimensional bioinformatic analysis. Our WES findings revealed a rare heterozygous gain-of-function variant (R496W) in the exon 9 of the PCSK9 gene as a causal factor for FH in this family. This variant was absent in healthy relatives of the proband and 200 healthy normolipidemic controls from Saudi Arabia. Furthermore, this variant has not been previously reported in various regional and global population genomic variant databases. Interestingly, this variant is classified as "likely pathogenic" (PP5) based on the variant interpretation guidelines of the American College of Medical Genetics (ACMG). Computational functional characterization suggested that this variant could destabilize the native PCSK9 protein and alter its secondary and tertiary structural features. In addition, this variant was predicted to negatively influence its ligand-binding ability with LDLR and Alirocumab antibody molecules. This rare PCSK9 (R496W) variant is likely to expand our understanding of the genetic basis of FH in Saudi Arabia. This study also provides computational structural insights into the genotype-protein phenotype relationship of PCSK9 pathogenic variants and contributes to the development of personalized medicine for FH patients in the future.

Cardiovascular Disease in Saudi Arabia: Facts and the Way Forward

Cardiovascular diseases (CVDs) remain a major health concern globally. While some risk factors for CVDs are non-modifiable, other determinants like obesity, hypertension, type-2 diabetes and dyslipidemia can be mitigated by a wide plethora of measures to control CVD morbidity and mortality. Those determinants have been on the rise in Saudi Arabia, exacerbated by sedentary lifestyle. The Saudi Vision 2030 aims to reduce CVD clinical and economic burden and to scale up vitality and longevity; in a new era of comprehensive healthcare. From a health economics standpoint, CVDs entail a burden on healthcare systems directly through expenditure and indirectly through years living with the disease, low productivity, premature morbidity and mortality. This manuscript reviews current CV health and unmet needs in Saudi Arabia, discusses G20 countries' initiatives on primary prevention: public health measures, awareness programs; and proposes national registries and digital solutions to facilitate population-specific research, improve CV surveillance and alleviate CVD burden in Saudi Arabia.

Management and clinical outcomes of patients with homozygous familial hypercholesteremia in Saudi Arabia

We report the incidence, patient characteristic with clinical outcomes in patients with homozygous familial hypercholesterolemia (HoFH) in Saudi Arabia. This is a retrospective and prospective, single center study which included 37 patients 14 years and older enrolled and followed up between 2018-2021 for three years. 46% were females, 78% were offspring of consanguineous marriage. LDLR mutation was in 78% and LDL-C/LDLRAP in 3% of patients. Mean LDL-C at the first presentation was 14.2±3.7 mmol/L, average Dutch lipid score was 20.9±6.24. LDL apheresis was performed on 70% of patients. Most patients were on ezetimibe (92%), high-dose statins ( 84%) and  PCSK9 inhibitors (32%). 48.6% had aortic stenosis, out of which 30% had severe aortic stenosis. Ten underwent aortic valve surgery (5 mechanical valve, 3 Ross procedure, 1 aortic valve repair, 1 bioprosthetic valve) and one had transcatheter aortic valve implantation (TAVI). Coronary artery bypass surgery (CABG) was performed on 32% and percutaneous intervention (PCI) on 11% of patients. HoFH patients have complex diseases with high morbidity and mortality, and benefit from a highly specialized multidisciplinary clinic to address their clinical needs. Although there are several therapeutic agents on the horizon, early diagnosis, and treatment of HoFH remain critical to optimize patient outcomes.

Multizonal observational study conducted by clinical practitioners on evolocumab use in subjects with hyperlipidemia in Saudi Arabia and Kuwait: Results from the ZERBINI study

OBJECTIVES

Dyslipidemia is a prevalent condition with significant morbidity and mortality across the world, including in the Arabian Gulf. The present study aimed to describe the characteristics of patients receiving evolocumab in clinical practice.

METHODS

ZERBINI was a multi-country, observational, retrospective/prospective study of subjects receiving evolocumab as part of routine clinical management of their hyperlipidemia. This regional publication reports on adult participants from Saudi Arabia and Kuwait who have had ≥1 dose of evolocumab before enrollment and ≤6 months' prior exposure to evolocumab. Patient characteristics and treatment persistence data were collected in addition to baseline and follow-up data up to 12 months post-evolocumab initiation.

RESULTS

Overall, 225 patients were included from two sites, Saudi Arabia (N = 155) and Kuwait (N = 70). Mean age was comparable across sites and most patients had baseline coronary artery disease and/or hypertension. Baseline LDL-C levels (mean ± SD 3.6 ± 1.4 mmol/L in Saudi Arabia, 3.1 ± 1.4 mmol/L in Kuwait) were reduced by approximately 57%-62% in the first 6 months after evolocumab initiation (1.5 ± 1.2 mmol/L in Saudi Arabia [n = 63], 1.2 ± 0.8 mmol/L in Kuwait [n = 28]). This decrease was maintained over the 12-month follow-up period. Most patients achieved ACC 2018 LDL-C goals (<1.8 mmol/L; 74.6% in Saudi Arabia, 93.1% in Kuwait) and ESC 2019 LDL-C goals (<1.4 mmol/L; 66.7% in Saudi Arabia, 75.9% in Kuwait) in the first 6 months after evolocumab initiation. Medication persistence with evolocumab was high (up to 90.7%). Evolocumab had a favorable safety profile and no treatment-emergent adverse events were observed at either site.

CONCLUSION

Evolocumab is an effective lipid-lowering treatment in local populations. LDL-C goal achievement is increased when evolocumab is added to background lipid-lowering therapy with high tolerability and persistence. Long-term follow-up and large-scale data are needed to further support these observations.

New Trends and Therapies for Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is associated with an elevated risk of atherosclerosis. The finding of monogenic defects indicates higher atherosclerotic risk in comparison with hypercholesterolemia of other etiologies. However, in heterozygous FH, cardiovascular risk is heterogeneous and depends not only on high cholesterol levels but also on the presence of other biomarkers and genes. The development of atherosclerosis risk scores specific for heterozygous FH and the use of subclinical coronary atherosclerosis imaging help with identifying higher-risk individuals who may benefit from further cholesterol lowering with PCSK9 inhibitors. There is no question about the extreme high risk in homozygous FH, and intensive LDL-cholesterol-lowering therapy must be started as soon as possible. These patients have gained life free of events in comparison with the past, but a high atherosclerosis residual risk persists. Furthermore, there is also the issue of aortic and supra-aortic valve disease development. Newer therapies such as inhibitors of microsomal transfer protein and angiopoietin-like protein 3 have opened the possibility of LDL-cholesterol normalization in homozygous FH and may provide an alternative to lipoprotein apheresis for these patients. Gene-based therapies may provide more definite solutions for lowering high LDL cholesterol and consequent atherosclerosis risk for people with FH.

Familial hypercholesterolaemia and coronary risk factors among patients with angiogram-proven premature coronary artery disease in an Asian cohort

BACKGROUND

Familial hypercholesterolaemia (FH) patients have elevated levels of low-density lipoprotein cholesterol, rendering them at high risk of premature coronary artery disease (PCAD). However, the FH prevalence among angiogram-proven PCAD (AP-PCAD) patients and their status of coronary risk factors (CRFs) have not been reported in the Asian population.

OBJECTIVES

This study aimed to (1) determine the prevalence of clinically diagnosed FH among AP-PCAD patients, (2) compare CRFs between AP-PCAD patients with control groups, and (3) identify the independent predictors of PCAD.

METHODS

AP-PCAD patients and FH patients without PCAD were recruited from Cardiology and Specialist Lipid Clinics. Subjects were divided into AP-PCAD with FH (G1), AP-PCAD without FH (G2), FH without PCAD (G3) and normal controls (G4). Medical records were collected from the clinic database and standardised questionnaires. FH was clinically diagnosed using Dutch Lipid Clinic Network Criteria.

RESULTS

A total of 572 subjects were recruited (males:86.4%; mean±SD age: 55.6±8.5years). The prevalence of Definite, Potential and All FH among AP-PCAD patients were 6%(19/319), 16% (51/319) and 45.5% (145/319) respectively. G1 had higher central obesity, family history of PCAD and family history of hypercholesterolaemia compared to other groups. Among all subjects, diabetes [OR(95% CI): 4.7(2.9,7.7)], hypertension [OR(95% CI): 14.1(7.8,25.6)], FH [OR(95% CI): 2.9(1.5,5.5)] and Potential (Definite and Probable) FH [OR(95% CI): 4.5(2.1,9.6)] were independent predictors for PCAD. Among FH patients, family history of PCAD [OR(95% CI): 3.0(1.4,6.3)] and Definite FH [OR(95% CI): 7.1(1.9,27.4)] were independent predictors for PCAD.

CONCLUSION

Potential FH is common among AP-PCAD patients and contributes greatly to the AP-PCAD. FH-PCAD subjects have greater proportions of various risk factors compared to other groups. Presence of FH, diabetes, hypertension, obesity and family history of PCAD are independent predictors of PCAD. FH with PCAD is in very-high-risk category, hence, early management of modifiable CRFs in these patients are warranted.

The Prevalence and Genetic Spectrum of Familial Hypercholesterolemia in Qatar Based on Whole Genome Sequencing of 14,000 Subjects

Familial hypercholesterolemia (FH) is an inherited disease characterized by reduced efficiency of low-density lipoprotein-cholesterol (LDL-C) removal from the blood and, consequently, an increased risk of life-threatening early cardiovascular complications. In Qatar, the prevalence of FH has not been determined and the disease, as in many countries, is largely underdiagnosed. In this study, we combined whole-genome sequencing data from the Qatar Genome Program with deep phenotype data from Qatar Biobank for 14,056 subjects to determine the genetic spectrum and estimate the prevalence of FH in Qatar. We used the Dutch Lipid Clinic Network (DLCN) as a diagnostic tool and scrutinized 11 FH-related genes for known pathogenic and possibly pathogenic mutations. Results revealed an estimated prevalence of 0.8% (1:125) for definite/probable cases of FH in the Qatari population. We detected 16 known pathogenic/likely pathogenic mutations in LDLR and one in PCSK9; all in a heterozygous state with high penetrance. The most common mutation was rs1064793799 (c.313+3A >C) followed by rs771019366 (p.Asp90Gly); both in LDLR. In addition, we identified 18 highly penetrant possibly pathogenic variants, of which 5 were Qatari-specific, in LDLR, APOB, PCSK9 and APOE, which are predicted to be among the top 1% most deleterious mutations in the human genome but further validations are required to confirm their pathogenicity. We did not detect any homozygous FH or autosomal recessive mutations in our study cohort. This pioneering study provides a reliable estimate of FH prevalence in Qatar based on a significantly large population-based cohort, whilst uncovering the spectrum of genetic variants associated with FH.

Is Liver Transplant Curative in Homozygous Familial Hypercholesterolemia? A Review of Nine Global Cases

INTRODUCTION

Homozygous familial hypercholesterolemia (HoFH) is a rare, life-threatening, inherited condition characterized by extremely elevated levels of low-density lipoprotein cholesterol (LDL-C). Patients are at high risk of atherosclerotic cardiovascular disease, adverse cardiovascular events, and associated early mortality. Liver transplant is sometimes used with curative intent. The objective of the current case series was to evaluate the follow-up of a range of patients who have undergone liver transplant for the treatment of HoFH.

METHODS

Patients with clinical and/or genetic diagnoses of HoFH were treated according to local practices in four units in Europe and the Middle East. All patients underwent liver transplantation. Baseline and long-term follow-up data were collected, including LDL-C levels, DNA mutations, lipid-lowering medications, and complications due to surgery and immunosuppressive therapy.

RESULTS

Nine patients were included with up to 22 years' follow-up (mean ± SD 11.7 ± 11.7 years; range 0.5-28 years). Three of the patients died as a result of complications of transplant surgery (mortality rate 33%). Among the surviving six patients, four required continued lipid-lowering therapy (LLT) to maintain LDL-C levels and two patients show signs of increasing LDL-C levels that require management. One case (11%) required two consecutive transplants to achieve a viable graft and is awaiting a third transplant because of graft failure.

CONCLUSIONS

Liver transplant did not enable attainment of recommended LDL-C targets in most patients with HoFH, and the majority of patients still required post-transplant LLT. Liver transplant was not curative in most of the patients with HoFH followed. Guidelines suggest that transplant is a treatment of last resort if contemporary treatments are not available or possible.

Bima A, Almukadi H, Ibrahim Kutbi H, Jayasheela Shetty P, Ahmad Shaik N, Banaganapalli B. Identifying Significant Genes and Functionally Enriched Pathways in Familial Hypercholesterolemia Using Integrated Gene Co-Expression Network Analysis

Familial hypercholesterolemia (FH) is a monogenic lipid disorder which promotes atherosclerosis and cardiovascular diseases. Owing to the lack of sufficient published information, this study aims to identify the potential genetic biomarkers for FH by studying the global gene expression profile of blood cells. The microarray expression data of FH patients and controls was analyzed by different computational biology methods like differential expression analysis, protein network mapping, hub gene identification, functional enrichment of biological pathways, and immune cell restriction analysis. Our results showed the dysregulated expression of 115 genes connected to lipid homeostasis, immune responses, cell adhesion molecules, canonical Wnt signaling, mucin type O-glycan biosynthesis pathways in FH patients. The findings from expanded protein interaction network construction with known FH genes and subsequent Gene Ontology (GO) annotations have also supported the above findings, in addition to identifying the involvement of dysregulated thyroid hormone and ErbB signaling pathways in FH patients. The genes like CSNK1A1, JAK3, PLCG2, RALA, and ZEB2 were found to be enriched under all GO annotation categories. The subsequent phenotype ontology results have revealed JAK3I, PLCG2, and ZEB2 as key hub genes contributing to the inflammation underlying cardiovascular and immune response related phenotypes. Immune cell restriction findings show that above three genes are highly expressed by T-follicular helper CD4⁺ T cells, naïve B cells, and monocytes, respectively. These findings not only provide a theoretical basis to understand the role of immune dysregulations underlying the atherosclerosis among FH patients but may also pave the way to develop genomic medicine for cardiovascular diseases.

Comorbidities with Familial Hypercholesterolemia (FH): A Systematic Review

Familial hypercholesterolemia (FH) is linked to high levels of low-density lipoprotein cholesterol (LDL-C), atherosclerotic, and aortic stenosis to a lesser extent. We looked at the incidence of prevalent comorbid disorders other than cardiovascular disease (CVD), such as diabetes, chronic kidney disease (CKD), hypertension, and cancer in heterozygous FH (HeFH) patients. PubMed, Web of Science, and Google Scholar were searched systematically for studies reporting comorbidities in FH patients. Finally, 23 studies were included after excluding duplicates, papers with unrelated titles, reviews, abstracts, and papers with not sufficient data. Results showed that among the comorbidities that have been studied; FH patients had a greater prevalence of CKD. In terms of diabetes, the data are inconsistent, with some research indicating a higher prevalence of diabetes in FH patients and mostly indicating the opposite. Polymorphism study showed that hypertension has been linked to FH; however, the prevalence of the hypertensive subjects varies among FH groups. In comparison to the general population, cancer was found to have a lower or similar prevalence in FH patients. More research is needed in this area due to the variability of the results of the relationship between diabetes and FH and the small number of studies on cancer. In conclusion only CKD can be considered as an important and prevalent comorbidity in FH population after CVDs.

Generalizability of GWA-Identified Genetic Risk Variants for Metabolic Traits to Populations from the Arabian Peninsula

The Arabian Peninsula, located at the nexus of Africa, Europe, and Asia, was implicated in early human migration. The Arab population is characterized by consanguinity and endogamy leading to inbreeding. Global genome-wide association (GWA) studies on metabolic traits under-represent the Arab population. Replicability of GWA-identified association signals in the Arab population has not been satisfactorily explored. It is important to assess how well GWA-identified findings generalize if their clinical interpretations are to benefit the target population. Our recent study from Kuwait, which performed genome-wide imputation and meta-analysis, observed 304 (from 151 genes) of the 4746 GWA-identified metabolic risk variants replicable in the Arab population. A recent large GWA study from Qatar found replication of 30 GWA-identified lipid risk variants. These complementing studies from the Peninsula increase the confidence in generalizing metabolic risk loci to the Arab population. However, both the studies reported a low extent of transferability. In this review, we examine the observed low transferability in the context of differences in environment, genetic correlations (allele frequencies, linkage disequilibrium, effect sizes, and heritability), and phenotype variance. We emphasize the need for large-scale GWA studies on deeply phenotyped cohorts of at least 20,000 Arab individuals. The review further presents GWA-identified metabolic risk variants generalizable to the Arab population.

Familial Hypercholesterolemia (FH) Registry Worldwide: A Systematic Review

Familial hypercholesterolemia (FH) is the most common genetic disease which accelerates the development of premature coronary artery disease (CAD) in young adults if remains untreated. The overall prevalence of FH is currently unknown and is usually underdiagnosed and undertreated worldwide. FH registry in different geographical area is a mission that helps early diagnosis of FH patients in the general population. PubMed, ISI Web of Science, Scopus, and Google Scholar were searched systematically for studies and reports on the FH registry using related keywords. Finally, 27 studies were included in this review. Most of the studies used the CASCADE screening method based on 1 or more than 1 of the 3 well-established FH criteria namely, the Dutch Lipid Clinic Network, Simon Broome Register, or Make Early Diagnosis to Prevent Early Death criteria. Except for a small number of studies that the genetic and molecular methods were used, in other studies only clinical diagnosis was applied. All these studies claimed that the FH registry causes the identification of many new cases as a result of used CASCADE screening and referral to lipid clinics. They concluded that the FH registry increases general and also physician awareness on FH prevalence and its related complications which in the long-term will improve FH management. This indicates that in other parts of the world, the FH registry should be established as well so that more accurate statistics on the prevalence of this disease can be found worldwide which would help in diagnosis and prevention.

Clinical Features of Familial Hypercholesterolemia in Children and Adults in EAS-FHSC Regional Center for Rare Diseases in Poland

BACKGROUND

Familial hypercholesterolemia (FH) is a genetic autosomal co-dominant metabolic disorder leading to elevated circulating concentrations of low-density lipoprotein cholesterol (LDL-C). Early development of atherosclerotic cardiovascular disease (ASCVD) is common in affected patients. We aimed to evaluate the characteristics and differences in the diagnosis and therapy of FH children and adults. Methods: All consecutive patients who were diagnosed with FH, both phenotypically and with genetic tests, were included in this analysis. All patients are a part of the European Atherosclerosis Society FH-Study Collaboration (FHSC) regional center for rare diseases at the Polish Mother's Memorial Hospital Research Institute (PMMHRI) in Lodz, Poland. Results: Of 103 patients with FH, there were 16 children (15.5%) at mean age of 9 ± 3 years and 87 adults aged 41 ± 16; 59% were female. Children presented higher mean levels of total cholesterol, LDL-C, and high-density lipoprotein cholesterol (HDL-C) measured at the baseline visit (TC 313 vs. 259 mg/dL (8.0 vs. 6.6 mmol/L), p = 0.04; LDL 247 vs. 192 mg/dL (6.3 vs. 4.9 mmol/L), p = 0.02, HDL 53 vs. 48 mg/dL (1.3 vs. 1.2 mmol/L), p = 0.009). Overall, 70% of adult patients and 56% of children were prescribed statins (rosuvastatin or atorvastatin) on admission. Combination therapy (dual or triple) was administered for 24% of adult patients. Furthermore, 13.6% of adult patients and 19% of children reported side effects of statin therapy; most of them complained of muscle pain. Only 50% of adult patients on combination therapy achieved their treatment goals. None of children achieved the treatment goal.

CONCLUSIONS

Despite a younger age of FH diagnosis, children presented with higher mean levels of LDL-C than adults. There are still urgent unmet needs concerning effective lipid-lowering therapy in FH patients, especially the need for greater use of combination therapy, which may allow LDL-C targets to be met in most of the patients.