$Unique_ID{BRK03838} $Pretitle{} $Title{Hyperchylomicronemia} $Subject{Hyperchylomicronemia Buerger-Gruetz Syndrome Exogenous Hypertriglyceridemia Fredrickson Type I Hyperlipoproteinemia Essential Familial Hyperlipemia Fat-Induced Hyperlipemia Idiopathic Familial Hyperlipemia Retention Hyperlipemia Hyperlipidemia I Hyperlipoproteinemia Type I Lipoprotein Lipase Deficiency, Familial Familial Apolipoprotein C-II Deficiency Hyperlipoproteinemia Type V} $Volume{} $Log{} Copyright (C) 1987, 1988, 1989 National Organization for Rare Disorders, Inc. 474: Hyperchylomicronemia ** IMPORTANT ** It is possible the main title of the article (Hyperchylomicronemia) is not the name you expected. Please check the SYNONYMS listing on the next page to find alternate names, disorder subdivisions, and related disorders covered by this article. Synonyms Buerger-Gruetz Syndrome Exogenous Hypertriglyceridemia Fredrickson Type I Hyperlipoproteinemia Essential Familial Hyperlipemia Fat-Induced Hyperlipemia Idiopathic Familial Hyperlipemia Retention Hyperlipemia Hyperlipidemia I Hyperlipoproteinemia Type I Lipoprotein Lipase Deficiency, Familial Information on the following disorders can be found in the Related Disorders section of this report: Hyperlipoproteinemia Type V Familial Apolipoprotein C-II Deficiency General Discussion ** IMPORTANT ** The information contained in the Rare Disease Database is provided for educational purposes only. It should not be used for diagnostic or treatment purposes. If you wish to obtain more information about this disorder, please contact your personal physician and/or the agencies listed in the "Resources" section of this report. Hyperchylomicronemia is a rare hereditary inborn error of metabolism characterized by a massive accumulation of fatty droplets (chylomicrons) in blood plasma, and a corresponding increase of the blood plasma concentration of fatty substances called triglycerides. The concentration of another fatty substance called "very low density lipoprotein" (VLDL) is usually normal. The disorder is caused by the absence of the enzyme lipoprotein lipase. Symptoms Hyperchylomicronemia is characterized by an abnormally high blood concentration of droplets of a fatty substance called chylomicrons after a patient eats fatty foods. The first symptoms are skin lesions called eruptive xanthomas. These xanthomas are raised whitish-yellow colored skin nodules on a slightly red base. They vary in size from 0.1 to 0.3 inches in diameter, but are often clustered and may grow together to form larger plaques. The number of nodules may vary from a few to hundreds. They are usually located over the buttocks, shoulders, and extremities. However, lesions may be found on any site including the face and mucous membranes. Patients may mistake the lesions for acne. Eruptive xanthomas are neither painful nor itchy. They usually appear within a few days after triglyceride levels in the blood plasma have begun to increase. They contain a yellowish greasy substance and sometimes milky fluid. They disappear again when the increased fat in blood plasma (lipemia) starts to vanish. Only a slight discoloration finally remains. Besides the skin symptoms, the most common manifestations of Hyperchylomicronemia are episodes of abdominal pain. Intensity, duration, and localization of episodes are variable. The attacks may be associated with lack of appetite (anorexia), nausea, abdominal distension, fever, and diarrhea. Some patients with the disorder may not experience abdominal pain. Inflammation of the pancreas, sometimes with bleeding, often occurs when triglyceride levels are excessively high. Enlargement of the liver and spleen occurs particularly among infants and children with Hyperchylomicronemia. The enlargement of these organs may vary, often in parallel with the fat content of the diet. Large cells that swallow other cell material (macrophages) that have incorporated chylomicrons often appear in the spleen and sometimes in bone marrow of these patients. In the presence of excessive fatty substances in the blood (hyperlipemia) the arteries and veins in the outer parts of the eye's retina have a milky or tomato juice appearance. The back of the eyeball (fundus) may appear pale pink upon examination by an ophthalmologist. The change is related to the degree of lipemia. The retina may contain white fatty deposits. Blood circulation in the retina may also become disturbed, and narrowing of the blood vessels and bleeding may occasionally occur. These symptoms can affect the vision of patients with Hyperchylomicronemia. Causes Hyperchylomicronemia is a hereditary disorder transmitted by autosomal recessive genes. (Human traits including the classic genetic diseases, are the product of the interaction of two genes for that condition, one received from the father and one from the mother. In recessive disorders, the condition does not appear unless a person inherits the same defective gene from each parent. If one receives one normal gene and one gene for the disease, the person will be a carrier for the disease, but usually will show no symptoms. The risk of transmitting the disease to the children of a couple, both of whom are carriers for a recessive disorder, is twenty-five percent. Fifty percent of their children will be carriers, but healthy as described above. Twenty-five percent of their children will receive both normal genes, one from each parent and will be genetically normal.) The disorder is caused by a deficiency of the enzyme lipoprotein lipase which normally breaks down the fatty substances called lipoproteins. This results in an excessively high level of chylomicrons in the blood. Affected Population Hyperchylomicronemia is a very rare disorder which is present at birth. It affects males and females in equal numbers. Related Disorders Symptoms of the following disorders are similar to those of Hyperchylomicronemia. Comparisons may be useful for a differential diagnosis: Hyperlipoproteinemia Type V (Mixed Hyperlipemia) is thought to be a recessive hereditary disorder characterized by an abnormally high level of chylomicrons in the blood. Other fatty substances called prebetalipoproteins are also present in high concentrations in the blood. Blood plasma has a milky white appearance. During overnight refrigeration of plasma, a layer of chylomicrons rises to the top. The underlying plasma is cloudy in patients with Hyperchylomicronemia Type V, but clear in those with Type I of the disorder. Fatty changes in the retina of the eye may occur in both of these disorders. However, Type V is less severe than Type I Hyperlipoproteinemia. Familial Apolipoprotein C-II Deficiency is a rare autosomal recessive hereditary disorder. It is characterized by a deficiency of apolipoprotein C-II, a factor needed for functioning of the enzyme lipoprotein lipase, causing an accumulation of chylomicrons and very low density lipoproteins (VLDL) in blood plasma. Recurrent attacks of pancreas infection (pancreatitis) may also occur. Therapies: Standard Restriction of fat in the diet is the most effective treatment for Hyperchylomicronemia. However, at the same time an adequate intake of essential fatty acids must be maintained. The reduction of fat in the diet must be compensated by an increase in carbohydrates. Part of the fat calories can be supplied in the form of medium-chain triglycerides (MCT), though many patients do not tolerate these well. Additionally, the use of alcohol and drugs such as estrogens (which increase synthesis of triglycerides in the body), should be avoided. During pregnancy patients with Hyperchylomicronemia need strict dietary control and monitoring of blood triglyceride levels. Genetic counseling is recommended for families of children with Hyperchylomicronemia. Therapies: Investigational This disease entry is based upon medical information available through December 1988. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder. Resources For more information on Hyperchylomicronemia, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 National Digestive Diseases Information Clearinghouse Box NDDIC Bethesda, MD 20892 (301) 468-6344 Research Trust for Metabolic Diseases in Children Golden Gates Lodge, Weston Rd. Crewe CW1 1XN, England Telephone: (0270) 250244 For genetic information and genetic counseling referrals, please contact: March of Dimes Birth Defects Foundation 1275 Mamaroneck Avenue White Plains, NY 10605 (914) 428-7100 Alliance of Genetic Support Groups 35 Wisconsin Circle, Suite 440 Chevy Chase, MD 20815 (800) 336-GENE (301) 652-5553 References THE METABOLIC BASIS OF INHERITED DISEASE, 5th ed.: John B. Stanbury, et al., ed.; McGraw Hill, 1983. Pp. 622-632. MENDELIAN INHERITANCE IN MAN, 6th ed.: Victor A. McKusick; Johns Hopkins University Press, 1986. P. 1042. LIPAEMIA RETINALIS IN A 29-DAY-OLD INFANT WITH TYPE I HYPERLIPOPROTEINAEMIA: S. Hayasaka, et al.; British Journal Ophthalmol (April 1985: issue 69(4)). Pp. 280-282.