👤 Arman Qamar

Low-density lipoprotein cholesterol (LDL-C) levels <100 mg/dL are generally considered normal. We tested the controversial hypothesis that a subset of individuals with 'normal' LDL-C levels may have a non-negligible risk of coronary artery disease (CAD) due to inherited factors, including monogenic variants and polygenic risk scores (PGS). A retrospective analysis of a prospective cohort from the Genomic Health Initiative at Endeavor Health, including 7880 participants without a prior diagnosis of CAD and not on statins at recruitment. Participants were stratified by baseline LDL-C levels and followed for incident CAD. The association of CAD risk with carrier status for pathogenic/likely pathogenic (P/LP) variants in Among participants, 31.2 % had LDL-C <100 mg/dL (normal), 39.5 % had LDL-C 100-129 mg/dL, and 29.3 % had LDL-C ≥130 mg/dL. Over a median follow-up of 8 years, CAD was diagnosed in 5.3 %, 6.9 %, and 7.6 % of participants in these LDL-C groups, respectively. Among those with normal LDL-C, CAD incidence rose to 9.5 % in individuals with high genetic risk (P/LP variants and/or high PGS). Genetic risk was significantly associated with CAD in multivariable models ( Individuals with 'normal' LDL-C levels can have substantial CAD risk if they carry high genetic risk. These findings underscore the importance of incorporating genetic information into CAD risk assessment, even among those with traditionally normal lipid profiles. Show less

Inborn errors of metabolism (IEM) are frequently underdiagnosed in low-resource settings due to limited diagnostic infrastructure. We hypothesized that an integrated clinical-genomic approach could improve diagnosis and management of these conditions. Nineteen Pakistani families with clinically suspected IEM underwent systematic clinical assessment, available biochemical testing, and whole-exome sequencing (WES). Variants were classified according to ACMG/AMP guidelines using evidence from population databases, in silico prediction tools, segregation analysis, and genotype-phenotype correlation. Clinical diagnoses and management strategies were reassessed based on molecular findings. WES provided a molecular diagnosis in 90% (17/19) of families and enabled targeted therapeutic interventions in 70% (13/19). However, clinical outcomes were variable due to advanced disease in some cases and limited follow-up. Seven novel variants were identified in CYP27B1, DYM, MTTP, ALDH3A2, USP53, BRAF, and JAG1, while twelve recurrent mutations were detected in PIGN, GCDH, CLCN7, RNASEH2C, ABCB11, MPV17, IDUA, SMPD1, FBP1, SLC37A4, ACADM, and UGT1A1. Integrating genomic findings with clinical reassessment improved diagnostic precision. An integrated clinical-genomic approach enabled accurate diagnosis of pediatric IEM in resource-limited settings, with particular utility in children with metabolic disorders in a consanguineous population. Identification of both novel and recurrent variants expanded the genotypic and phenotypic spectrum of these disorders and highlighted the clinical utility of genomic diagnostics in optimizing patient care. Show less

Current genetic testing for coronary artery disease (CAD) primarily targets monogenic variants in individuals with severe hypercholesterolemia. Whether supplementing monogenic testing with polygenic risk scores for CAD and Lp(a; lipoprotein[a]) levels [PRS A genetic probability for CAD (GenProb In the UK Biobank development cohort, PVs, polygenic risk scores for CAD and PRS GenProb Show less

Alzheimer's disease (AD) ranks as the most prevalent neurodegenerative disorder with dementia and it accounts for more than 70% of all cases. Despite extensive reporting on the experimental investigation of Show less

Consumer demand for tasty and quality meat has been quickly increasing. This study investigated how dietary supplemented rutin affects meat quality, muscle fatty acid profile, and antioxidant capacity in the Chinese indigenous Qingyuan partridge chicken. A cohort of 180 healthy 119-day-old chickens was subjected to a randomized assignment into three groups, identified as the control, R200, and R400 groups, with respective supplementation of 0, 200, and 400 mg/kg of rutin. The results revealed insignificance in growth performance, namely, average daily gain, average daily feed intake, and feed-to-gain ratio, across the various treatment groups ( Show less

A major goal of biomedicine is to understand the function of every gene in the human genome. Loss-of-function mutations can disrupt both copies of a given gene in humans and phenotypic analysis of such 'human knockouts' can provide insight into gene function. Consanguineous unions are more likely to result in offspring carrying homozygous loss-of-function mutations. In Pakistan, consanguinity rates are notably high. Here we sequence the protein-coding regions of 10,503 adult participants in the Pakistan Risk of Myocardial Infarction Study (PROMIS), designed to understand the determinants of cardiometabolic diseases in individuals from South Asia. We identified individuals carrying homozygous predicted loss-of-function (pLoF) mutations, and performed phenotypic analysis involving more than 200 biochemical and disease traits. We enumerated 49,138 rare (<1% minor allele frequency) pLoF mutations. These pLoF mutations are estimated to knock out 1,317 genes, each in at least one participant. Homozygosity for pLoF mutations at PLA2G7 was associated with absent enzymatic activity of soluble lipoprotein-associated phospholipase A2; at CYP2F1, with higher plasma interleukin-8 concentrations; at TREH, with lower concentrations of apoB-containing lipoprotein subfractions; at either A3GALT2 or NRG4, with markedly reduced plasma insulin C-peptide concentrations; and at SLC9A3R1, with mediators of calcium and phosphate signalling. Heterozygous deficiency of APOC3 has been shown to protect against coronary heart disease; we identified APOC3 homozygous pLoF carriers in our cohort. We recruited these human knockouts and challenged them with an oral fat load. Compared with family members lacking the mutation, individuals with APOC3 knocked out displayed marked blunting of the usual post-prandial rise in plasma triglycerides. Overall, these observations provide a roadmap for a 'human knockout project', a systematic effort to understand the phenotypic consequences of complete disruption of genes in humans. Show less

Triglyceride-rich lipoproteins (TRLs) are causal contributors to the risk of developing coronary artery disease (CAD). Apolipoprotein C-III (apoC-III) is a component of TRLs that elevates plasma triglycerides (TGs) through delaying the lipolysis of TGs and the catabolism of TRL remnants. Recent human genetics approaches have shown that heterozygous loss-of-function mutations in APOC3, the gene encoding apoC-III, lower plasma TGs and protect from CAD. This observation has spawned new interest in therapeutic efforts to target apoC-III. Here, we briefly review both currently available as well as developing therapies for reducing apoC-III levels and function to lower TGs and cardiovascular risk. These therapies include existing options including statins, fibrates, thiazolidinediones, omega-3-fatty acids, and niacin, as well as an antisense oligonucleotide targeting APOC3 currently in clinical development. We review the mechanisms of action by which these drugs reduce apoC-III and the current understanding of how reduction in apoC-III may impact CAD risk. Show less

Retinitis pigmentosa (RP) is a devastating form of retinal degeneration, with significant social and professional consequences. Molecular genetic information is invaluable for an accurate clinical diagnosis of RP due to its high genetic and clinical heterogeneity. Using a gene capture panel that covers 163 of the currently known retinal disease genes, including 48 RP genes, we performed a comprehensive molecular screening in a collection of 123 RP unsettled probands from a wide variety of ethnic backgrounds, including 113 unrelated simplex and 10 autosomal recessive RP (arRP) cases. As a result, 61 mutations were identified in 45 probands, including 38 novel pathogenic alleles. Interestingly, we observed that phenotype and genotype were not in full agreement in 21 probands. Among them, eight probands were clinically reassessed, resulting in refinement of clinical diagnoses for six of these patients. Finally, recessive mutations in CLN3 were identified in five retinal degeneration patients, including four RP probands and one cone-rod dystrophy patient, suggesting that CLN3 is a novel non-syndromic retinal disease gene. Collectively, our results underscore that, due to the high molecular and clinical heterogeneity of RP, comprehensive screening of all retinal disease genes is effective in identifying novel pathogenic mutations and provides an opportunity to discover new genotype-phenotype correlations. Information gained from this genetic screening will directly aid in patient diagnosis, prognosis, and treatment, as well as allowing appropriate family planning and counseling. Show less

Evidence is sparse about the genetic determinants of major lipids in Pakistanis. Variants (n=45 000) across 2000 genes were assessed in 3200 Pakistanis and compared with 2450 Germans using the same gene array and similar lipid assays. We also did a meta-analysis of selected lipid-related variants in Europeans. Pakistani genetic architecture was distinct from that of several ethnic groups represented in international reference samples. Forty-one variants at 14 loci were significantly associated with levels of HDL-C, triglyceride, or LDL-C. The most significant lipid-related variants identified among Pakistanis corresponded to genes previously shown to be relevant to Europeans, such as CETP associated with HDL-C levels (rs711752; P<10(-13)), APOA5/ZNF259 (rs651821; P<10(-13)) and GCKR (rs1260326; P<10(-13)) with triglyceride levels; and CELSR2 variants with LDL-C levels (rs646776; P<10(-9)). For Pakistanis, these 41 variants explained 6.2%, 7.1%, and 0.9% of the variation in HDL-C, triglyceride, and LDL-C, respectively. Compared with Europeans, the allele frequency of rs662799 in APOA5 among Pakistanis was higher and its impact on triglyceride concentration was greater (P-value for difference <10(-4)). Several lipid-related genetic variants are common to Pakistanis and Europeans, though they explain only a modest proportion of population variation in lipid concentration. Allelic frequencies and effect sizes of lipid-related variants can differ between Pakistanis and Europeans. Show less