Criteria for diagnosis of probable heterozygous<unk>  (98% specificity) 1st degree relative general population age cholesterol mg/dL mmol/L mg/dL mmol/L 220 > 5.7 > 270 > 7.0 LDL-C > 155 > 4.0 > 200 > 5.2 20–29 total > 240 > 6.2 > 290 > 7.5 LDL-C > 170 > 4.4 > 220 > 5.7 30–39 total > 270 > 7.0 > 340 > 8.8 LDL-C > 190 > 5.0 > 240 > 6.2 ≥ 40 total > 290 > 7.5 > 360 > 9.3 LDL-C > 205 > 5.3 > 260 > 6.7 First-degree relatives are parents, offspring, brothers, and sisters Approximately 85% of individuals with this disorder have not been diagnosed and consequently are not receiving lipid-lowering treatments. Physical examination findings can help a physician make the diagnosis of<unk> . Tendon xanthomas are seen in 20-40% of individuals with<unk>  and are pathognomonic for the condition. A xanthelasma or corneal arcus may also be seen. These common signs are supportive of the diagnosis, but are non-specific findings. Lipid measurements Cholesterol levels may be determined as part of health screening for health insurance or occupational health, when the external physical signs such as xanthelasma, xanthoma, arcus are noticed, symptoms of cardiovascular disease develop, or a family member has been found to have<unk> . A pattern compatible with hyperlipoproteinemia type IIa on the Fredrickson classification is typically found: raised level of total cholesterol, markedly raised level of low-density lipoprotein (LDL), normal level of high-density lipoprotein (HDL), and normal level of triglycerides. Total cholesterol levels of 350–550 mg/dL are typical of heterozygous<unk>  while total cholesterol levels of 650–1000 mg/dL are typical of homozygous<unk> . The LDL is typically above the 75th percentile, that is, 75% of the healthy population would have a lower LDL level. Cholesterol levels can be drastically higher in people with<unk>  who are also obese. Mutation analysis On the basis of the isolated high LDL and clinical criteria (which differ by country), genetic testing for LDL receptor mutations and ApoB mutations can be performed. Mutations are detected in between 50 and 80% of cases; those without a mutation often have higher triglyceride levels and may in fact have other causes for their high cholesterol, such as combined hyperlipidemia due to metabolic syndrome. Differential diagnosis<unk>  needs to be distinguished from familial combined hyperlipidemia and polygenic<unk> . Lipid levels and the presence of xanthomata can confirm the diagnosis. Sitosterolemia and cerebrotendineous xanthomatosis are two rare conditions that can also present with premature atherosclerosis and xanthomas. The latter condition can also involve neurological or psychiatric manifestations, cataracts, diarrhea and skeletal abnormalities.
Familial hypercholesterolemia
Familial hypertriglyceridemia
Combined hyperlipidemia
Apolipoprotein B deficiency
Familial multiple lipomatosis
Marfanoid
Fruitarianism
Fabry disease