Homozygous familial hypercholesterolaemia in two sisters misdiagnosed as rheumatoid arthritis.

To cite: Ayesh (Haj Yousef ) MH, Shatnawi A, Khdeir M, et al. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2016216097 DESCRIPTION A female patient aged 25 years and her younger sister aged 23 years were referred to the haematology clinic at our hospital suffering from irondeficiency anaemia. Before taking the medical history of the two patients, the older patient told the treating physician (the author) that she and her sister had been experiencing yellow swellings on their joints since they were 10 years of age. The patients were told that the cause of the swellings was rheumatoid arthritis (RA), but despite treatment for RA, the swellings increased in size. No related signs were observed among relatives, including the father and mother. On physical examination, both sisters had xanthoma of the hands, elbows, knees and ankles (figures 1–3). Lipid profiles of both patients showed high cholesterol (22 and 23 mmol/L) and low-density lipoprotein (LDL) levels (21 and 22 mmol/L), and normal levels of triglyceride (1.36 and 1.46 mmol/L) and HDL (0.8 and 0.85 mmol/ L), respectively. The father and mother had high cholesterol (10.54 and 9.23 mmol/L) and LDL (8.1and 6.7 mmol/L) levels, respectively, consistent with heterozygous familial hypercholesterolaemia (HeFH). We found parents to be first cousins.