Renal failure is the major cause of morbidity and mortality in complete LCAT deficiency, while in partial deficiency (fish eye disease) major cause of morbidity is visual impairment due to corneal opacity. These patients have low HDL cholesterol but surprisingly premature atherosclerosis is not seen. However, there are some reported cases.

The disorder affects about 1 out of 1,000,000 people, however epidemiological data are limited and there are regional differences due to cofounder effect (e.g. in Canada) or intermarriage.

Lipoprotein lipase deficiency (also known as "familial chylomicronemia syndrome", "chylomicronemia", "chylomicronemia syndrome" and "hyperlipoproteinemia type Ia") is a rare autosomal recessive lipid disorder caused by a mutation in the gene which codes lipoprotein lipase. As a result, afflicted individuals lack the ability to produce lipoprotein lipase enzymes necessary for effective breakdown of triglycerides.

Familial dysautonomia is seen almost exclusively in Ashkenazi Jews and is inherited in an autosomal recessive fashion. Both parents must be carriers in order for a child to be affected. The carrier frequency in Jewish individuals of Eastern European (Ashkenazi) ancestry is about 1/30, while the carrier frequency in non-Jewish individuals is unknown. If both parents are carriers, there is a one in four, or 25%, chance with each pregnancy for an affected child. Genetic counseling and genetic testing is recommended for families who may be carriers of familial dysautonomia.

Worldwide, there have been approximately 600 diagnoses recorded since discovery of the disease, with approximately 350 of them still living.

Familial dysalbuminemic hyperthyroxinemia is a type of hyperthyroxinemia associated with mutations in the human serum albumin gene.

The term was introduced in 1982.

Screening among family members of people with known FH is cost-effective. Other strategies such as universal screening at the age of 16 were suggested in 2001. The latter approach may however be less cost-effective in the short term. Screening at an age lower than 16 was thought likely to lead to an unacceptably high rate of false positives.

A 2007 meta-analysis found that "the proposed strategy of screening children and parents for familial hypercholesterolaemia could have considerable impact in preventing the medical consequences of this disorder in two generations simultaneously." "The use of total cholesterol alone may best discriminate between people with and without FH between the ages of 1 to 9 years."

Screening of toddlers has been suggested, and results of a trial on 10,000 one-year-olds were published in 2016. Work was needed to find whether screening was cost-effective, and acceptable to families.

Both conditions are treated with fibrate drugs, which act on the peroxisome proliferator-activated receptors (PPARs), specifically PPARα, to decrease free fatty acid production. Statin drugs, especially the synthetic statins (atorvastatin and rosuvastatin), can decrease LDL levels by increasing hepatic reuptake of LDL due to increased LDL-receptor expression.

Familial dysbetalipoproteinemia or type III hyperlipoproteinemia (also known as remnant hyperlipidemia, "remnant hyperlipoproteinaemia", "broad beta disease" and "remnant removal disease") is a condition characterized by increased total cholesterol and triglyceride levels, and decreased HDL levels.

Apolipoprotein B deficiency (also known as "Familial defective apolipoprotein B-100") is an autosomal dominant disorder resulting from a missense mutation which reduces the affinity of apoB-100 for the low-density lipoprotein receptor (LDL Receptor) . This causes impairments in LDL catabolism, resulting in increased levels of low-density lipoprotein in the blood. The clinical manifestations are similar to diseases produced by mutations of the LDL receptor, such as familial hypercholesterolemia. Treatment may include, niacin or statin or ezetimibe.

It is also known as "normotriglyceridemic hypobetalipoproteinemia".

This condition is caused by a mutation in apolipoprotein E (ApoE), that serves as a ligand for the liver receptors for chylomicrons, IDL and VLDL or Very Low Density lipoprotein receptors. The normal ApoE turns into the defective ApoE2 form due to a genetic mutation. This defect prevents the normal metabolism of chylomicrons, IDL and VLDL, otherwise known as remnants, and therefore leads to accumulation of cholesterol within scavenger cells (macrophages) to enhance development and acceleration of atherosclerosis.

Both the familial type and Fish-eye disease are autosomal recessive disorders caused by mutations of the "LCAT" gene located on chromosome 16q22.1, which is the long (q) arm of chromosome 16 a position 22.1. Both diseases are very rare with ~70 reported cases of familial LCAT deficiency and ~30 cases of fish-eye disease.

Acquired hyperlipidemias (also called secondary dyslipoproteinemias) often mimic primary forms of hyperlipidemia and can have similar consequences. They may result in increased risk of premature atherosclerosis or, when associated with marked hypertriglyceridemia, may lead to pancreatitis and other complications of the chylomicronemia syndrome. The most common causes of acquired hyperlipidemia are:

- diabetes mellitus

- Use of drugs such as thiazide diuretics, beta blockers, and estrogens

Other conditions leading to acquired hyperlipidemia include:

- Hypothyroidism

- Kidney failure

- Nephrotic syndrome

- Alcohol consumption

- Some rare endocrine disorders and metabolic disorders

Treatment of the underlying condition, when possible, or discontinuation of the offending drugs usually leads to an improvement in the hyperlipidemia.

Another acquired cause of hyperlipidemia, although not always included in this category, is postprandial hyperlipidemia, a normal increase following ingestion of food.

The two forms of this lipid disorder are:

- Familial combined hyperlipidemia (FCH) is the familial occurrence of this disorder, probably caused by decreased LDL receptor and increased ApoB.

- Acquired combined hyperlipidemia is extremely common in patients who suffer from other diseases from the metabolic syndrome ("syndrome X", incorporating diabetes mellitus type II, hypertension, central obesity and CH). Excessive free fatty acid production by various tissues leads to increased VLDL synthesis by the liver. Initially, most VLDL is converted into LDL until this mechanism is saturated, after which VLDL levels elevate.

These unclassified forms are extremely rare:

- Hyperalphalipoproteinemia

- Polygenic hypercholesterolemia

The disease is typically progressive, leading to fulminant liver failure and death in childhood, in the absence of liver transplantation. Hepatocellular carcinoma may develop in PFIC-2 at a very early age; even toddlers have been affected.

The global prevalence of FH is approximately 10 million people. In most populations studied, heterozygous FH occurs in about 1:500 people, but not all develop symptoms. Homozygous FH occurs in about 1:1,000,000.

"LDLR" mutations are more common in certain populations, presumably because of a genetic phenomenon known as the "founder effect"—they were founded by a small group of individuals, one or several of whom was a carrier of the mutation. The Afrikaner, French Canadians, Lebanese Christians, and Finns have high rates of specific mutations that make FH particularly common in these groups. "APOB" mutations are more common in Central Europe.

It is not known how mevalonate kinase mutations cause the febrile episodes, although it is presumed that other products of the cholesterol biosynthesis pathyway, the prenylation chains (geranylgeraniol and farnesol) might play a role.

Migraine itself is a very common disorder, occurring in 15–20% of the population. Hemiplegic migraine, be it familial or spontaneous, is less prevalent, 0.01% prevalence according to one report. Women are three times more likely to be affected than males.

Familial Isolated Vitamin E Deficiency also known as Ataxia With Vitamin E Deficiency is a rare autosomal recessive neurodegenerative disease. Symptoms are similar to those of Friedreich ataxia.

The outlook for patients with FD depends on the particular diagnostic category. Patients with chronic, progressive, generalized dysautonomia in the setting of central nervous system degeneration have a generally poor long-term prognosis. Death can occur from pneumonia, acute respiratory failure, or sudden cardiopulmonary arrest in such patients.

Parents and patients should generally be educated regarding daily eye care and early warning signs of corneal problems as well as the use of punctal cautery. This education has resulted in decreased corneal scarring and need for more aggressive surgical measures such as tarsorrhaphy, conjunctival flaps, and corneal transplants.

The cause of the disease is unknown. It was originally thought that the epidermal changes were secondary to profound malnutrition as a result of protein-losing enteropathy. Recent findings have called this hypothesis into question; specifically, the hair and nail changes may not improve with improved nutrition.

Other conditions consisting of multiple hamartomatous polyps of the digestive tract include Peutz-Jeghers syndrome, juvenile polyposis, and Cowden disease. Related polyposis conditions are familial adenomatous polyposis, attenuated familial adenomatous polyposis, Birt–Hogg–Dubé syndrome and MUTYH.

Familial Isolated Vitamin E Deficiency is caused by mutations in the gene for a-tocopherol transfer protein.

Genetic contributions are usually due to the additive effects of multiple genes, though occasionally may be due to a single gene defect such as in the case of familial hypercholesterolaemia.

Genetic abnormalities are in some cases completely responsible for hypercholesterolemia, such as in familial hypercholesterolemia, where one or more genetic mutations in the autosomal dominant APOB gene exist, the autosomal recessive "LDLRAP1" gene, autosomal dominant familial hypercholesterolemia ("HCHOLA3") variant of the "PCSK9" gene, or the LDL receptor gene. Familial hypercholesterolemia affects about one in five hundred people.

May–White syndrome is a rare familial progressive myoclonus epilepsy with lipomas, deafness, and ataxia. This syndrome is probably a familial form of mitochondrial encephalomyopathy.

Virtually all people with the syndrome have mutations in the gene for mevalonate kinase, which is part of the HMG-CoA reductase pathway, an important cellular metabolic pathway. Indeed, similar fever attacks (but normal IgD) have been described in patients with mevalonic aciduria – an inborn error of metabolism now seen as a severe form of HIDS.