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Disease Profile

Mitochondrial myopathy and sideroblastic anemia

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

Adolescent

ICD-10

G71.3

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)

Myopathy with lactic acidosis and sideroblastic anemia; MLASA; Myopathy, lactic acidosis and sideroblastic anemia;

Categories

Blood Diseases; Congenital and Genetic Diseases; Metabolic disorders;

Summary

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

Orpha Number: 2598

Definition
Mitochondrial myopathy and sideroblastic anemia belongs to the heterogeneous family of metabolic myopathies. It is characterised by progressive exercise intolerance manifesting in childhood, onset of sideroblastic anaemia around adolescence, lactic acidaemia, and mitochondrial myopathy.

Epidemiology
Less than 10 cases have been described so far.

Etiology
A 656C-->T mutation in the nuclear pseudouridine synthase 1 gene (PUS1), localised to 12q24.33, has recently been identified in some patients. Deficient pseudouridylation of mitochondrial tRNAs may be responsible for the oxidative phosphorylation disorder.

Diagnostic methods
Muscle biopsy demonstrates low activity of complexes 1 and 4 of the respiratory chain and paracrystalline inclusions can be revealed in most mitochondria by electron microscopy.

Genetic counseling
Transmission is autosomal recessive.

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
80%-99% of people have these symptoms
Anemia
Low number of red blood cells or hemoglobin
0001903
Distichiasis
0009743
EMG abnormality
0003457
Generalized limb muscle atrophy
Generalized muscle wasting
0009055
High palate
Elevated palate
Increased palatal height

[ more ]

0000218
Lactic acidosis
Increased lactate in body
0003128
Long philtrum
0000343
Micrognathia
Little lower jaw
Small jaw
Small lower jaw

[ more ]

0000347
Mitochondrial myopathy
0003737
Muscular hypotonia
Low or weak muscle tone
0001252
Myopathy
Muscle tissue disease
0003198
30%-79% of people have these symptoms
Delayed puberty
Delayed pubertal development
Delayed pubertal growth
Pubertal delay

[ more ]

0000823
Glaucoma
0000501
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation

[ more ]

0001249
Kyphosis
Hunched back
Round back

[ more ]

0002808
Microcephaly
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Reduced head circumference
Small head circumference

[ more ]

0000252
Scoliosis
0002650
Short nose
Decreased length of nose
Shortened nose

[ more ]

0003196
Percent of people who have these symptoms is not available through HPO
Autosomal recessive inheritance
0000007
Cytochrome C oxidase-negative muscle fibers
0003688
Erythroid hyperplasia
0012132
Exercise intolerance
Decreased ability to exercise
Inability to exercise

[ more ]

0003546
Failure to thrive
Faltering weight
Weight faltering

[ more ]

0001508
Hypochromic anemia
0001931
Increased serum ferritin
Elevated serum ferritin
High ferritin level
Increased ferritin
Increased serum ferritin level

[ more ]

0003281
Increased serum lactate
0002151
Microcytic anemia
0001935
Pallor
0000980
Pappenheimer bodies
0020081
Progressive muscle weakness
0003323
Sideroblastic anemia
0001924

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.

Where to Start

  • The Muscular Dystrophy Association has developed a resource called "Facts About Myopathies" that discusses commonly asked questions regarding myopathies. Click on the link above to view this information page.

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 Mitochondrial myopathy and sideroblastic anemia. Click on the link to view a sample search on this topic.