Rare Endocrinology News

Disease Profile

Micro syndrome

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.

Unknown

Age of onset

Childhood

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ICD-10

Q87.0

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)

WARBM; Warburg micro syndrome

Categories

Congenital and Genetic Diseases; Eye diseases; Nervous System Diseases

Summary

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

Orpha Number: 2510

Definition
Micro syndrome is an autosomal recessive disorder caracterised by ocular and neurodevelopmental defects and by microgenitalia. It presents with severe intellectual disability, microcephaly, congenital cataract, microcornea, microphthalmia, agenesis/hypoplasia of the corpus callosum, and hypogenitalism.

Epidemiology
Since its initial description, 26 cases of Micro syndrome have been reported in the literature.

Clinical description
With exception of the ophthalmologic features, the clinical and dysmorphic findings are either unapparent or subtle in the early postnatal period.

Etiology
Mutations in RAB3GAP, a gene showing linkage to a region of homozygosity at 2q21.3, have been identified in some families. The RAB3GAP gene encodes a member of the Rab3 protein family, which is involved in regulated exocytosis of neurotransmitters and hormones. It has been suggested that the hypogenitalism is hypothalamic in origin, and that the ocular and neurodevelopmental defects result from abnormal neurotransmitter vesicular transport and exocytosis.

Diagnostic methods
Ocular findings are the most reliable diagnostic signs of Micro syndrome, especially during infancy. Pathognomonic ophthalmologic findings include microphthalmia, microcornea, cataract, atonic pupils, mild optic atrophy, and severe cortical vision impairment.

Differential diagnosis
Micro syndrome should be considered in any infant with congenital cataract.

Management and treatment
There is no specific treatment for Micro syndrome and the management is symptomatic. The conventional approach used for congenital cataract should be recommended.

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
Anteverted nares
Nasal tip, upturned
Upturned nasal tip
Upturned nose
Upturned nostrils

[ more ]

0000463
Aplasia/Hypoplasia of the corpus callosum
0007370
Cataract
Clouding of the lens of the eye
Cloudy lens

[ more ]

0000518
Cerebral visual impairment
0100704
Cryptorchidism
Undescended testes
Undescended testis

[ more ]

0000028
Delayed puberty
Delayed pubertal development
Delayed pubertal growth
Pubertal delay

[ more ]

0000823
Global developmental delay
0001263
High palate
Elevated palate
Increased palatal height

[ more ]

0000218
Intellectual disability, severe
Early and severe mental retardation
Mental retardation, severe
Severe mental retardation

[ more ]

0010864
Joint stiffness
Stiff joint
Stiff joints

[ more ]

0001387
Microcephaly
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Reduced head circumference
Small head circumference

[ more ]

0000252
Microcornea
Cornea of eye less than 10mm in diameter
0000482
Microphthalmia
Abnormally small eyeball
0000568
Muscular hypotonia
Low or weak muscle tone
0001252
Optic atrophy
0000648
Pachygyria
Fewer and broader ridges in brain
0001302
Short nose
Decreased length of nose
Shortened nose

[ more ]

0003196
Short philtrum
0000322
Short stature
Decreased body height
Small stature

[ more ]

0004322
Spasticity
Involuntary muscle stiffness, contraction, or spasm
0001257
Wide nasal bridge
Broad nasal bridge
Broad nasal root
Broadened nasal bridge
Increased breadth of bridge of nose
Increased breadth of nasal bridge
Increased width of bridge of nose
Increased width of nasal bridge
Nasal bridge broad
Wide bridge of nose
Widened nasal bridge

[ more ]

0000431
30%-79% of people have these symptoms
Abnormality of retinal pigmentation
0007703
Abnormality of visual evoked potentials
0000649
Cerebral cortical atrophy
Decrease in size of the outer layer of the brain due to loss of brain cells
0002120
Clitoral hypoplasia
Small clitoris
Underdeveloped clit

[ more ]

0000060
Generalized hirsutism
Excessive hairiness over body
0002230
Hypoplasia of penis
Underdeveloped penis
0008736
Hypoplastic labia minora
Underdeveloped inner lips
0000064
Intrauterine growth retardation
Prenatal growth deficiency
Prenatal growth retardation

[ more ]

0001511
Kyphosis
Hunched back
Round back

[ more ]

0002808
Low-set, posteriorly rotated ears
0000368
Macrotia
Large ears
0000400
Micrognathia
Little lower jaw
Small jaw
Small lower jaw

[ more ]

0000347
Scoliosis
0002650
5%-29% of people have these symptoms
Abnormal localization of kidney
Abnormal localisation of kidneys
0100542
Cerebellar vermis hypoplasia
0001320
Hydronephrosis
0000126
Peripheral neuropathy
0009830
Retinal coloboma
Hole in the back of the eye
0000480
Seizure
0001250

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) lists the subtypes and associated genes for Micro syndrome in a table called Phenotypic Series. Each entry in OMIM includes 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 Micro syndrome. Click on the link to view a sample search on this topic.