Study part 3. Families from study part 1 and 2, who are considered severely affected by atherosclerosis, evaluated on a basis of family size, number of affected and severity of disease, will be selected. Family members (index patients, 1st degree relatives and if relevant also their 1st degree relatives) who consent,will be included in study part 3. Contact with relatives who have not yet participated in the project will be attempted as in study part 2. A traditional risk profile and a blood sample for DNA analysis (exome sequencing) will be requested if it has not already been obtained. The analysis takes place at Department of Molecular Medicine (MOMA), AUH, Skejby, who have the required equipment, software and laboratory expertise in performing the tests as well as the bioinformatic analysis. First, genomic DNA is purified and fragmented to a size of 200-500 base pairs. Illumina TruSeq libraries (to be used with the exome sequencing) will be produced at a Caliper Sciclone-robot where the exome enrichment with Nimblegens EZ in solution Exome v3 kit will also take place. The dataanalysis will be taking place at MOMA under the guidance of the MOMA staff. First sequences will be trimmed and aligned to the humane genome. Second, alignments will be fine-tuned before variants will be called, including single nucleotide variants and insertions/deletions of various size. The interpretation of the data will be taking place in the software program Cartagenia, which gives access to an abundance of public and commercial databases and also offers the opportunity of integrating private databases. Variants will be filtered on a basis of frequency, gene position, existing knowledge and different in-silico prediction tools. Possible significant findings will be validated by Sanger sequencing.