Browsing by Author "Hotakainen, Ronja"

Diabetes is a group of chronic metabolic disorders caused by the inability of the body to produce or utilize insulin efficiently. Globally, diabetes affects over 422 million people (WHO 2014) and one third of the patients suffer from diabetes-related complications, which cause a considerable economic burden on the healthcare. Diabetic kidney disease (DKD) is one of the most severe complications, since one in five patients develop end-stage renal disease, which requires dialysis or kidney transplantation for survival. In addition, diabetes is a risk factor for cardiovascular disease (CVD), the most common cause of mortality among individuals with diabetes. Conventional clinical risk factors for both DKD and CVD have been established and include an altered lipoprotein profile, an abnormal glucose balance and hypertension. While the clinical risk factors are fairly well recognized, the genetic background of both DKD and CVD is rather unknown. The aim of this thesis was to study the effects of rare genetic variants altering lipids and other cardiometabolic risk factors and to determine their impact on diabetic complications. This study focused on loss of function and missense variants from whole exome- (N=500) and whole genome sequencing data (N=600) in type 1 diabetics from the Finnish Diabetic Nephropathy Study cohort. Single variant and gene-based association analysis were used to detect lipid-associated genetic variants and suggestive genes involved in lipid metabolism. Meta-analysis of whole exome- and whole genome single variants was performed to increase the sample size and detect additional lipid-associated variants. Three lipid-associated variants were genotyped in a cohort of 3000 patients to confirm the detected associations. Single variant association analysis detected a novel, previously unpublished, 21bp deletion located in the RBM47 gene, which was associated with lower apoC-III serum concentrations. To fully understand the impact of the 21bp deletion in RBM47 on apoC-III, further studies investigating the role of RBM47 in lipid metabolism are requested. Furthermore, single variant meta-analysis detected several lipid-associated variants. We showed that the rs451195 in PPIC was significantly associated with DKD. This study sheds light on the genetic background of diabetic dyslipidemia.