The aim is to study the prevalence of abdominal aortic aneurysm in first degree relatives and the risk to develop AAA in individuals with heredity for AAA compared with the population ( without heredity for AAA).The study i based on national registers in Sweden with high coverage and capacity of linkage between different registers.

The study is designed as a retrospective, descriptive case-control population based national study. By using national registers, eligible patients diagnosed with AAA during the time period 2010-2024 will be identified, ( treated and untreated). The time period includes when screening was established in Sweden resulting in a large cohort of diagnosed men. Hence, individuals with diagnosed with AAA will be identified through registers at the National health and bord of welfare (Cause of death register, National patient register, Discharge register). Matched controls by sex, age (+/- 1 year), region and income (low,medium, high) will be identified in a ratio of x 4 from Statistic Sweden. These individuals will then be linked to the multigeneration register for identification of their first degree relatoves (FDR). In the finalstep, the FDR will be linked to NBHW register in order to evaluate if the individuals are diagnosed with AAA (rAAA or iAAA) or not. Socioeconomic data and comorbidity will also be collected for FDR, indexperson and matched controls.

Overall aim: To improve the understanding of the hereditary patterns for aortic disease, with specific consideration of regional differences and sex.

Hypothesis: An increased risk to develop any aortic disease will be detected in persons with one or more first-degree-relatives diagnosed with an aortic disease, which will remain although standard adjustments will be considered (age, sex, comorbidity,socioeconomic status).

Aims: 1)To describe the risk for female and male first-degree relatives (FDR) to female and male persons diagnosed with AAA (index persons) to develop a diagnosed AAA,compared to the population. 2) Identification of possible predictive associated risk factors (modifiable/non-modifiable, protective or negative) age, sex, region, other cardiovascular diseases,comorbidities, several FDRs, socioeconomic situation, multilevel aortic disease thatinfluences the hereditary risk.3)To describe the distribution of female and male first-degree relatives (FDR) to female and male persons diagnosed with AAA (index persons) to be diagnosed with a ruptured AAA rather than intact AAA, compared to the population.

Inclusion Criteria:

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Exclusion Criteria:

• younger than 45 years.

Individuals with the diagnose AAA or the cause of death AAA in Sweden 2010-2024. The first-degree relatives have been identified through the Swedish multigeneration register and then a register based identifiaction if having AAA or not. All men and female over 45 years old are included.

Individual participant data will not be shared with external parties due to Swedish legislation on personal data protection (GDPR) and restrictions governing access to national health register data. Data will only be accessible to the research team named in the ethical approval