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Disease Profile

Chylomicron retention disease

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
<1 / 1 000 000

< 331

US Estimated

< 514

Europe Estimated

Age of onset

Childhood

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ICD-10

E78.6

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

CMRD; Lipid transport defect of intestine; Hypobetalipoproteinemia with accumulation of apolipoprotein b-like protein in intestinal cells

Categories

Congenital and Genetic Diseases; Digestive Diseases; Endocrine Diseases;

Summary

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
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Orpha Number: 71

Definition
Chylomicron retention disease (CRD) is a type of familial hypocholesterolemia characterized by malnutrition, failure to thrive, growth failure, vitamin E deficiency and hepatic, neurologic and ophthalmologic complications.

Epidemiology
About 55 cases have been described to date.

Clinical description
Chylomicron retention disease manifests in infancy or early childhood. Features include an abnormal lipid profile, failure to thrive, chronic malabsorptive diarrhea, vomiting and abdominal distension in early infancy (1-6 months), and vitamin E deficiency. Cardiomyopathy and muscular manifestations have also been described. Essential fatty acid (EFA) deficiency is especially severe early in life. Poor mineralization and delayed bone maturation can occur. Hepatic steatosis is common and hepatomegaly is reported to occur in about 20% of CRD patients. Neurologic complications (areflexia, ataxia, myopathy, sensory neuropathy) and ophthalmologic complications (minor visual abnormalities) are less severe in CRD than in other types of familial hypocholesterolemia.

Etiology
The SAR1B gene has been identified as the cause of CRD. More than 14 different mutations in about 30 patients have been described. This gene encodes the Sar1b protein, which is involved in the transport of chylomicrons (carriers of dietary lipids) from the endoplasmic reticulum to the Golgi apparatus. This mutation results in accumulation of pre-chylomicron transport vesicles in the cytoplasm of enterocytes. Genotyping has revealed that Anderson's disease and CRD are in fact the same condition.

Diagnostic methods
Diagnosis is often delayed because symptoms are nonspecific and hypocholesterolemia may be attributed to malnutrition secondary to chronic diarrhea. Diagnosis is based on a history of chronic diarrhea with fat malabsorption and a characteristic abnormal lipid profile: generally a 50% decrease in total cholesterol, LDL-cholesterol (LDL-C) and high-density lipoprotein-cholesterol (HDL-C) in the presence of normal triglycerides. Upper endoscopy and histology reveal fat-laden enterocytes. Elevated creatine kinase (CK) in patients with hypocholesterolemia may be suggestive of CRD. Genotyping makes it possible to identify the SAR1B gene mutations. Parental lipid screening may clarify the diagnosis. An absence of hypocholesterolemia in both parents favors CRD. Consanguinity is frequent in patients with the disorder.

Differential diagnosis
Differential diagnosis includes abetalipoproteinemia and other genetic hypocholesterolemias characterized by decreased LDL-C, such as homozygous hypobetalipoproteinemia (HBL; see these terms), and acquired disorders associated with low HDL-C.

Genetic counseling
The disease follows an autosomal recessive pattern of inheritance.

Management and treatment
Follow-up should be directed toward monitoring nutrition and growth, and treatment compliance. Management should focus on prevention and early detection of complications (hepatic, neuromuscular, retinal and bone). Control of vitamin E deficiency plays a key role in preventing neurological complications. Treatment includes fat-soluble vitamin supplements and large amounts of vitamin E. Vitamin A, in combination with vitamin E, may help to prevent ophthalmologic complications. Early vitamin D treatment makes it possible to prevent osteopenia. Vomiting, diarrhea and abdominal distension improve on a low-long chain fat diet. Dietary counseling is needed not only to monitor fat intake and improve symptoms, but also to maintain sufficient caloric and EFA intake.

Prognosis
Very long-term follow-up into adulthood is poorly documented.

Visit the Orphanet disease page for more resources.

Symptoms

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
100% of people have these symptoms
Diarrhea
Watery stool
0002014
Hypocholesterolemia
Decreased circulating cholesterol level
0003146
80%-99% of people have these symptoms
Elevated hepatic transaminase
High liver enzymes
0002910
Retinopathy
Noninflammatory retina disease
0000488
Steatorrhea
Fat in feces
0002570
30%-79% of people have these symptoms
Abdominal distention
Abdominal bloating
Abdominal swelling
Belly bloating
Bloating

[ more ]

0003270
Abnormality of vitamin metabolism
0100508
Failure to thrive
Faltering weight
Weight faltering

[ more ]

0001508
Growth delay
Delayed growth
Growth deficiency
Growth failure
Growth retardation
Poor growth
Retarded growth

[ more ]

0001510
Increased hepatocellular lipid droplets
0006565
Vomiting
Throwing up
0002013
5%-29% of people have these symptoms
EMG: myopathic abnormalities
0003458
Hepatic steatosis
Fatty infiltration of liver
Fatty liver

[ more ]

0001397
Visual impairment
Impaired vision
Loss of eyesight
Poor vision

[ more ]

0000505
1%-4% of people have these symptoms
Acanthocytosis
0001927
Areflexia
Absent tendon reflexes
0001284
Impaired proprioception
0010831
Percent of people who have these symptoms is not available through HPO
Autosomal recessive inheritance
0000007
Decreased LDL cholesterol concentration
0003563
Hypoalbuminemia
Low blood albumin
0003073
Hypotriglyceridemia
Low blood triglyceride levels
0012153
Impaired vibratory sensation
Decreased vibration sense
Decreased vibratory sense
Diminished vibratory sense
Impaired vibratory sense

[ more ]

0002495
Infantile onset
Onset in first year of life
Onset in infancy

[ more ]

0003593
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation

[ more ]

0001249
Malnutrition
0004395
Reduced tendon reflexes
0001315

Diagnosis

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Learn more

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Chylomicron retention disease. Click on the link to view a sample search on this topic.