Backgroud: Heterozygous familial hypercholesterolemia are either classical cases with high LDL-C levels, tendon xanthomas and LDL receptor gene mutation or probable cases with hypercholesterolemia without known LDL receptor gene mutations.
Aims & Objectives: This study was done to compare the severity of hypercholesterolemia and risk of CVD in classical and probable cases of heterozygous familial hypercholesterolemia in tertiary care hospitals of Karachi. This was a case-series done from June 2008 to July 2010 at Dr Ziauddin Hospital and National Institute of Cardiovascular Diseases, Karachi, Pakistan.
Methods: Out of more than 240 patients with dyslipidemia or premature coronary artery diseases 120 patients who had primary hypercholesterolemia and were found to have total cholesterol >230mg/dL and LDL-C >160mg/dL were included in the study. All these cases had premature coronary artery diseases or had a family history of coronary artery diseases. They were grouped as classical or probable cases depending on raised LDL-C, xanthelasmas, xanthoma, premature coronary artery diseases and LDL-R gene mutations. Their blood samples were collected after twelve hours fasting. PCR was done for mutation specific primers for exons 3, 4, 9 and 14.
Results: Out of these 120 patients with heterozygous familial hypercholesterolemia, classical cases with LDL-receptor gene mutation were 42(35%) and probable cases without LDL-receptor gene mutations were 78(65%). Eleven (27%) of these classical cases had severe hypercholesterolemia having total cholesterol (>290mg/dL) and LDL-C (>200mg/dL) and were found to have xanthelasmas, xanthomas and arcus cornealis.
Discussion/Conclusions: Amongst the HeFH patients from the tertiary care hospitals of Karachi, classical cases with tendon xanthomas and LDL receptor gene mutations had severe hypercholesterolemia with greater risk of CVD, they required more aggressive treatment. Probable cases were also at risk of CVD and needed statin therapy.