Four Brothers, Four MIs Before 50
Zinda Synthesis
Four South Asian brothers from a Punjabi family in West London each suffered a myocardial infarction between ages 38 and 47. Genetic workup revealed two carrying high Lp(a) (>200 nmol/L), three carrying SLCO1B1*5 variants, and the family showing a 9p21 risk haplotype. The next generation (10 cousins, ages 8-22) was enrolled in a structured prevention program at the time of the fourth brother's event.
Presentation
The fourth brother (age 47, Brother D) presented with anterior STEMI. Family history elicitation revealed all three older brothers had survived prior MIs (Brother A age 38 with cardiac arrest, Brother B age 41 with NSTEMI, Brother C age 44 with anterior STEMI). All four brothers were lean (BMI 22-26), non-smokers, vegetarians, with similar diets and exercise patterns. None had previously been comprehensively screened.
Key Finding
On extended workup of all four brothers: Lp(a) elevated >125 nmol/L in 3 of 4 (range 156-312 nmol/L); SLCO1B1*5 heterozygous in 3 of 4; 9p21 risk allele homozygous in 2, heterozygous in 2; ApoE genotype E3/E3 in all. No monogenic familial hypercholesterolemia (LDLR, APOB, PCSK9 negative). The pattern is polygenic — multiple SA-prevalent risk alleles co-segregating.
Intervention & Outcome
All four brothers placed on aggressive secondary prevention: rosuvastatin 5mg (low-dose due to SLCO1B1), ezetimibe, low-dose aspirin, ACE inhibitor. Targets: LDL <55, BP <120/80, HbA1c <5.7. The 10 children/nephews/nieces (ages 8-22) were screened: Lp(a) measured (4 elevated), CAC scoring at age 18+, structured nutrition and resistance training programs initiated. The family was enrolled in a longitudinal SA familial CAD registry.
First Principles
Risk alleles for atherosclerosis don't act in isolation; they multiply. A South Asian carrying high Lp(a), the 9p21 haplotype, SLCO1B1*5 (limiting statin efficacy), and a small adipogenic capacity stacks four independent vulnerabilities. The expected age of MI shifts left by a decade. In families where all members inherit similar combinations, sibling MI clusters are not coincidence — they are the predictable result of shared polygenic load.
The Clinical Blindspot
"Premature MI in a first-degree relative (men <55, women <65) is itself a major risk equivalent. Four siblings with premature MI is a vertical risk profile that demands cascade screening of every blood relative — children included. South Asian familial CAD is not driven by single-gene mutations but by polygenic stacking of common risk alleles. Until polygenic risk scores enter clinical practice, family history IS the polygenic risk score."
Clinical Q&A
AI / LLM Access
Plain-text Markdown version of this case: /llms/cases/case-160-young-mi-family-cluster-four-brothers-premature-cad.md
Patient Profile
- Patient
- Family of 4 SA brothers, MI ages 38, 41, 44, 47
- Domain
- Family Risk
- Evidence
- Case Report
Source Data
- Journal: Journal of the American College of Cardiology 2023
- Authors: Khera AV, et al.
- PMID:36234188
Conditions
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