1,329 calculators and references across 60 specialties, with formula confidence shown up front.
AF Polygenic Risk Score (AF-PRS): Explanation and Clinical Context The AF Polygenic Risk Score (AF-PRS) quantifies an individual's inherited genetic susceptibility to atrial fibrillation based on the cumulative effect of multiple risk alleles. It is derived from genome-wide association studies (GWAS) that identify common single nucleotide polymorphisms (SNPs) associated with AF risk. The PRS is calculated by summing
APOE Genotype Risk Index (E2/E3/E4 variants): Explanation and Clinical Context The Apolipoprotein E (APOE) gene has three major alleles: E2, E3, and E4. The combination of these alleles determines an individual's genotype, which significantly influences lifetime risk for Alzheimer's disease and cardiovascular outcomes. E2 allele is generally protective, E3 is neutral, and E4 increases risk, particularly in homozygous
CACNA1C Variant Long QT Risk Model — Explanation and Clinical Context This tool estimates relative arrhythmic risk in carriers of CACNA1C variants by combining well-recognized predictors from long QT syndrome (LQTS) literature — especially QTc duration and history of syncope or prior cardiac arrest — with gene-specific considerations such as experimentally demonstrated gain-of-function in CACNA1C. QTc elevation, espe
DES Gene Risk Stratification (proposed, literature-informed): Explanation and Clinical Context This calculator implements a pragmatic, composite risk tool for individuals with DES gene variants (desmin-related myofibrillar myopathy) that combines genotype (pathogenic/likely pathogenic vs VUS/negative), presence of clinical cardiomyopathy, left ventricular ejection fraction (LVEF), arrhythmic burden (non-sustained VT,
Explanation — (imaging-based) This tool implements an imaging-based composite risk index developed to stratify patients with dystrophin-associated cardiomyopathy (principally Duchenne muscular dystrophy, DMD) by combining the timing and severity of left ventricular dysfunction with the timing and severity of myocardial fibrosis detected by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR). The ind
: explanation and clinical context This prototype score combines genetic test results (presence of pathogenic/likely pathogenic variants in well-established aortic disease genes) with clinical risk features (family history, connective tissue disorder, bicuspid aortic valve, hypertension, smoking, age, and sex) to produce a single numeric value that stratifies risk into Low, Moderate, High, and Very high categories. G
Genetic Risk Score (GRS13) for Lipid Disorders: Explanation and Clinical Context The GRS13 is a polygenic risk score calculated from 13 single nucleotide polymorphisms (SNPs) associated with lipid abnormalities, including elevated LDL-C, low HDL-C, and hypertriglyceridemia. Each SNP contributes to the score based on the number of risk alleles (0,1,2) and their effect sizes derived from genome-wide association studies
Heart Failure Polygenic Risk Score (HF-PRS): Explanation and Clinical Context The Heart Failure Polygenic Risk Score (HF-PRS) quantifies an individual's genetic predisposition to heart failure by summing the weighted effects of multiple single nucleotide polymorphisms (SNPs) previously associated with the disease. It is calculated as the sum of the number of risk alleles for each SNP multiplied by its corresponding e
KCNQ1 / KCNH2 Mutation Severity Classifier: background and clinical context This classifier synthesizes information about variant type (truncating vs missense vs CNV), protein location (pore, voltage sensor, transmembrane, regulatory domains), predicted functional effect (loss-of-function, dominant-negative, gain-of-function), and clinical phenotype (QTc duration, syncope, cardiac arrest, family sudden cardiac death)
LDLR Variant Severity Score: Explanation and Clinical Context The LDLR Variant Severity Score is a tool developed to predict phenotypic severity in patients with familial hypercholesterolemia (FH) based on LDLR genetic variant type, LDL-C level, and the presence of tendon xanthomas. This scoring system integrates functional classification of LDLR variants (null, defective, or mild), biochemical phenotype (LDL-C conce
LMNA Mutation Risk Model (Sudden Cardiac Death in DCM): Explanation and Clinical Context The LMNA Mutation Risk Model predicts the 5-year risk of sudden cardiac death (SCD) in patients with dilated cardiomyopathy (DCM) carrying LMNA gene mutations. Key predictors include the presence of non-sustained ventricular tachycardia (NSVT), reduced left ventricular ejection fraction (LVEF < 45%), male sex, and the presence of
MYH7/MYBPC3 Mutation Severity Score - Explanation, clinical context and references This prototype score aggregates genotype (gene and variant class), allele status (heterozygous vs compound/biallelic), family history of sudden cardiac death, age at diagnosis, maximal left ventricular wall thickness, arrhythmic markers (non-sustained ventricular tachycardia), recent unexplained syncope, left ventricular outflow tract
PLN p.Arg14del arrhythmic risk model — explanation and clinical context This tool implements the primary phenotypic predictors selected in the multivariable PLN p.Arg14del prediction model published by Verstraelen et al. (European Heart Journal, 2021): left ventricular ejection fraction (LVEF; model parameterized per 1% decrease), 24-hour premature ventricular contraction (PVC) count (log-transformed), number of lead
Polygenic Risk Score (PRS) for Coronary Artery Disease (CAD-PRS): Explanation and Clinical Context The CAD-PRS quantifies an individual's genetic predisposition to coronary artery disease by summing the weighted effects of multiple single nucleotide polymorphisms (SNPs) identified from genome-wide association studies (GWAS). Each risk allele contributes a specific weight based on its effect size derived from large-sc
SCN5A Variant Pathogenicity Index: Explanation and Clinical Context The SCN5A Variant Pathogenicity Index is a clinically validated tool to estimate the likelihood that a given SCN5A gene variant contributes to arrhythmia disorders, including Brugada Syndrome and Long QT Syndrome type 3. It integrates multiple lines of evidence: variant type (missense, nonsense, frameshift, splice-site, in-frame indel), functional st
: Rationale, Interpretation & Clinical Context Truncating variants in the TTN gene (TTNtv) are among the most common genetic contributors to dilated cardiomyopathy (DCM) and have been associated with increased risk of heart failure, atrial fibrillation, and adverse cardiac events in multiple cohort studies. Risk modifiers identified across the literature include whether the TTNtv lies in exons with high proportion sp