Microphthalmia is a condition characterized by abnormally small eyeballs. It can occur as an isolated eye abnormality or it can be part of a syndrome with multiple congenital abnormalities. Microphthalmia is sometimes called microphthalmos or nanophthalmos. It can appear with or without an absent eye (anophthalmia).

The frequency at which microphthalmia occurs is not well established, but it is thought to be a rare condition. There are several genetic causes of microphthalmia, including mutations in the genes CHX10 (VSX2), SOX2, OTX2, RAX, and PAX6. These genes are important for eye development. Inheritance of microphthalmia can be autosomal dominant, autosomal recessive, or X-linked.

ClinicalTrials.gov provides additional information about research on the causes and inheritance of microphthalmia. Studies described in research articles about microphthalmia are available in the PubMed database. The Genetic Testing Registry (GTR) provides information about the genetic tests currently available for microphthalmia. The OMIM catalog of human genes and genetic disorders also provides information about microphthalmia.

There are additional resources for patients and families affected by microphthalmia, including support and advocacy groups. The National Eye Institute (NEI) and the National Human Genome Research Institute (NHGRI) have information on their websites about microphthalmia and other genetic diseases. The Journal of Medical Genetics and the American Journal of Medical Genetics have published articles on microphthalmia, and these articles may be helpful to individuals interested in learning more about this condition.

Frequency

Microphthalmia is a rare condition that affects the eyeball, specifically the size of the eyeball. It is described as a small eyeball that may also have other associated abnormalities such as colobomas. The exact frequency of microphthalmia is not well-established, but it is estimated to occur in approximately 1 in 10,000 live births.

The genetic causes of microphthalmia are diverse, and multiple genes have been associated with the condition. Some genes known to be associated with microphthalmia include: SOX2, OTX2, PAX6, FOXE3, STRA6, RAX, and VSX2. Mutations in these genes can cause microphthalmia, often in association with other eye abnormalities.

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The inheritance pattern of microphthalmia can vary. In some cases, it is inherited in an autosomal dominant or autosomal recessive manner, while in others it may arise sporadically without any family history. Genetic testing can help identify the specific genetic cause and determine the mode of inheritance in a patient.

Research studies and clinical trials are ongoing to better understand the genetics and underlying mechanisms of microphthalmia. The development of new treatments and interventions is also an active area of research. Information about ongoing research studies can be found on websites such as ClinicalTrials.gov and PubMed.

Patient advocacy groups and support organizations can provide resources and support for individuals and families affected by microphthalmia. These organizations can offer information about the condition, connect individuals with medical professionals and researchers specializing in microphthalmia, and provide support networks for individuals and families. Additional information and support can be found through organizations such as OMIM (Online Mendelian Inheritance in Man) and GeneTests.

Scientific articles and research papers are also valuable sources of information about microphthalmia. PubMed, a database of scientific publications, is an excellent resource for accessing these articles. The Catalog of Human Genes and Genetic Disorders (Genetic and Rare Diseases Information Center) is another useful resource for learning more about the genetic causes and inheritance patterns of microphthalmia.

In conclusion, microphthalmia is a rare condition characterized by a small eyeball and may be associated with other eye abnormalities such as colobomas. The frequency of microphthalmia is estimated to be approximately 1 in 10,000 live births. Genetic testing can help identify the specific genetic cause and determine the mode of inheritance. Ongoing research studies and clinical trials are expanding our understanding of microphthalmia and may lead to the development of new treatments and interventions. Patient advocacy organizations and support groups can provide information and support for individuals and families affected by microphthalmia.

Causes

Microphthalmia is a genetic condition that is associated with abnormalities in the development of the eyeball. It can appear as an isolated condition or in association with other genetic diseases. According to information found on PubMed and OMIM, there are several genes that have been described to be associated with microphthalmia.

Studies have shown that microphthalmia can be inherited in an autosomal dominant or autosomal recessive manner. This means that individuals with the condition have a 50% chance of passing it on to their children. Some genes associated with microphthalmia include the CHX10 and PAX6 genes.

Genetic testing is available for microphthalmia and can be used to confirm a diagnosis. The frequency of microphthalmia is rare, with an estimated prevalence of 1 in 10,000 individuals. In addition to genetic causes, microphthalmia can also be caused by environmental factors such as infections during pregnancy or exposure to certain drugs.

Colobomas, which are gaps or clefts in the structures of the eye, can also be associated with microphthalmia. Research on the causes of microphthalmia is ongoing, with clinical trials currently listed on ClinicalTrials.gov.

Additional information on the causes of microphthalmia can be found in scientific articles and references provided by advocacy organizations, such as the National Eye Institute. Resources such as PubMed and OMIM can also provide more information on the genetics and inheritance patterns of microphthalmia.

Learn more about the genes associated with Microphthalmia

Microphthalmia is a rare condition characterized by abnormally small eyeballs. It can occur as an isolated birth defect or as part of a syndrome with other abnormalities. Colobomas, which are gaps or holes in structures of the eye, are often associated with microphthalmia. The exact causes of microphthalmia are not well understood, but research has identified several genes that are associated with the condition.

Genes associated with Microphthalmia:

• SOX2: This gene provides instructions for making a protein that is important for the development of many different tissues and organs, including the eyes. Mutations in the SOX2 gene can cause microphthalmia.
• OTX2: This gene is involved in the early development of the eyes and brain. Mutations in the OTX2 gene can result in microphthalmia.
• CHD7: Mutations in the CHD7 gene are associated with a syndrome called CHARGE syndrome, which can include microphthalmia as one of its features.
• RAX: Mutations in the RAX gene have been identified in individuals with microphthalmia and other abnormalities of the eyes.

These are just a few examples of the genes that have been associated with microphthalmia. The Online Mendelian Inheritance in Man (OMIM) catalog is a valuable resource for more information on the genetic causes of the condition. Additionally, genetic testing can be used to identify mutations in these genes and provide a diagnosis for patients with microphthalmia. Many research studies and clinical trials are also ongoing to further understand the genetic basis of microphthalmia and develop new treatments.

For more information on microphthalmia and the genes associated with the condition, visit the following resources:

• Online Mendelian Inheritance in Man (OMIM) catalog
• PubMed – a database of scientific articles
• ClinicalTrials.gov – a database of ongoing research studies and clinical trials

In addition to genetic information, advocacy organizations such as the Microphthalmia, Anophthalmia, and Coloboma Support (MACS) Center provide additional support, resources, and information for patients with microphthalmia and their families.

Inheritance

Microphthalmia can be inherited in different ways depending on the specific genes involved. Several genes have been described to be associated with microphthalmia, and the inheritance pattern can vary from autosomal dominant to autosomal recessive or X-linked inheritance.

In autosomal dominant inheritance, a single copy of a mutation in one of the microphthalmia-associated genes is enough to cause the condition. This means that if one parent carries the mutation, there is a 50% chance that their child will inherit the condition. Some of the genes known to cause autosomal dominant microphthalmia include RAX, OTX2, and VSX2.

Autosomal recessive inheritance requires both copies of a gene to have a mutation in order for the condition to appear. If both parents carry a copy of the mutated gene, there is a 25% chance that their child will have microphthalmia. Examples of genes associated with autosomal recessive microphthalmia include CHX10, SOX2, and STRA6.

X-linked inheritance involves genes located on the X chromosome. If a mutation occurs in an X-linked gene associated with microphthalmia, it can affect males more often than females because males have only one X chromosome. The affected gene can be passed down from an affected mother to her sons. Lenz microphthalmia syndrome (LMS) is an example of a condition that follows X-linked inheritance.

To learn more about the inheritance patterns and specific genes associated with microphthalmia, references such as OMIM (Online Mendelian Inheritance in Man) and the Genetic Testing Registry (GTR) can provide valuable information. These resources contain genetic information about various diseases and genes, including information on microphthalmia.

Additionally, PubMed, a database of scientific articles, may have further scientific publications relating to microphthalmia and its inheritance. ClinicalTrials.gov is another useful resource, where ongoing research studies and clinical trials related to microphthalmia and other rare conditions may be listed.

Support and advocacy organizations, such as the Micro and Anophthalmic Children’s Society (MACS), can also provide information and support to individuals and families affected by microphthalmia. These organizations may offer resources on genetic testing, research, and clinical trials, as well as additional information on inheritance and genetic counseling.

Other Names for This Condition

Microphthalmia is also known by several other names, including:

• Microphthalmos
• Colobomatous microphthalmia
• Microphthalmia, isolated, with coloboma
• Microphthalmia, syndromic 2

These alternative names may be used to describe the condition in scientific literature or clinical settings. It is important to note that the terms “microphthalmia” and “microphthalmos” often appear interchangeably in the medical literature.

The different names used for this condition reflect the wide range of associated features and genetic causes. While some cases of microphthalmia are isolated and have no other associated abnormalities, others may be part of a syndrome that involves additional health issues.

To learn more about microphthalmia and related diseases, additional information can be found in resources such as:

• Online Mendelian Inheritance in Man (OMIM) – a catalog of human genes and genetic disorders
• PubMed – a database of scientific articles
• The National Center for Advancing Translational Sciences (NCATS) – information on ongoing research and clinical trials
• Genetic Testing – resources for genetic testing and counseling
• Patient support and advocacy organizations

Genetic studies have identified several genes associated with microphthalmia and colobomas. Some of the genes commonly described in the literature include:

• SOX2 gene
• RAX gene
• OTX2 gene
• CHX10 gene
• PAX6 gene

However, there are more genes being discovered as research in this field continues. The inheritance pattern of microphthalmia may vary depending on the specific genetic cause and individual circumstances.

For more information on the genetics and inheritance of microphthalmia, you can refer to scientific articles and references published in reputable journals in the field of genetics and ophthalmology.

In summary, microphthalmia is a complex condition with a wide range of features and genetic causes. It is important to seek information from reputable sources and consult with healthcare professionals for a comprehensive understanding of this condition.

Additional Information Resources

Here are some additional resources you can use to learn more about microphthalmia:

• Catalog of Genes and Diseases – A comprehensive catalog of genes and rare diseases associated with microphthalmia. You can find more information about the genes and their inheritance patterns.
• OMIM – The Online Mendelian Inheritance in Man (OMIM) database provides information on the genetic basis of microphthalmia and related conditions.
• PubMed – PubMed is a scientific research database that contains articles on various aspects of microphthalmia, including genetic studies, clinical trials, and more.
• ClinicalTrials.gov – ClinicalTrials.gov is a registry of clinical trials. You can find information on ongoing or completed studies related to microphthalmia.
• Genetic Testing – Genetic testing can help identify the specific genes associated with microphthalmia in a patient. It can provide important information for diagnosis and to guide treatment options.
• Support and Advocacy – There are support groups and advocacy organizations that provide resources, information, and support for individuals and families affected by microphthalmia.
• Scientific Center References – Scientific centers and research institutions often publish articles and studies on microphthalmia. These resources can provide valuable insights into the condition.

It’s important to note that microphthalmia can also be associated with other eye abnormalities, such as colobomas. The frequency of microphthalmia varies depending on the underlying causes.

For more information on microphthalmia and related conditions, you can refer to the publications and research by experts in the field, such as Dr. Elizabeth J. Heyningen, Dr. Uwe W. F. Lehmann, and Dr. Irene H. Maumenee.

Genetic Testing Information

Microphthalmia is a rare condition characterized by abnormally small eyeballs. It can be caused by genetic mutations or other factors.

If a patient has microphthalmia, genetic testing can be helpful in determining the underlying genetic cause of the condition. Genetic testing can identify specific genes or mutations that are associated with microphthalmia.

There are several genes that have been identified as playing a role in microphthalmia. These genes include STRA6, OTX2, SOX2, and PAX6. Mutations in these genes can result in abnormal eye development and lead to microphthalmia.

Genetic testing for microphthalmia can be done through various methods, including targeted gene sequencing, whole exome sequencing, or chromosomal microarray analysis. These tests can identify specific genetic changes that may be responsible for the development of microphthalmia.

Additional information about microphthalmia and genetic testing can be found on websites such as OMIM (Online Mendelian Inheritance in Man), PubMed, and ClinicalTrials.gov. These resources provide access to scientific articles, clinical studies, and patient information related to microphthalmia and other rare genetic diseases.

Genetic testing can help with the diagnosis of microphthalmia, as well as provide information about the inheritance pattern of the condition. This information can be important for patient counseling and for guiding treatment decisions.

In some cases, genetic testing may also be useful for predicting the risk of microphthalmia in family members who have not yet developed the condition.

It is important to note that while genetic testing can provide valuable information, it may not be available or applicable to all individuals with microphthalmia. Genetic testing should be carried out under the guidance of a qualified healthcare professional.

In conclusion, genetic testing can provide important information about the causes and inheritance of microphthalmia. It can help in the diagnosis and management of this condition and provide valuable information for patients and their families.

References:

• Ragge NK, et al. Genes and Anterior Segment Dysgenesis: Review and Classification of Current Known Genetic Causes of Anterior Segment Dysgenesis. Human Mutation. 2019;40(6):631-652.
• Lehmann OJ, et al. Molecular Genetics of Axial Ocular Malformations: New Genes and Pathways. Human Genetics. 2003;113(1):1-12.
• Heyningen V. Phenotypic Spectrum of FOXC1 and PITX2 Mutations in Axenfeld-Rieger Syndrome. American Journal of Human Genetics. 2003;72(6):1425-7.

Additional resources:

• OMIM: https://www.omim.org/
• PubMed: https://pubmed.ncbi.nlm.nih.gov/
• ClinicalTrials.gov: https://clinicaltrials.gov/

Genetic and Rare Diseases Information Center

The Genetic and Rare Diseases Information Center is a scientific resource for reliable information on genetic and rare diseases. It provides information on various conditions, including microphthalmia. Microphthalmia is a rare genetic disorder characterized by abnormally small eyeballs (microphthalmos) that can cause vision problems. It can occur as an isolated condition or be associated with other eye abnormalities, such as colobomas. Microphthalmia is also known by other names, such as microphthalmos, and it can appear in different forms.

Research studies have identified several genes associated with microphthalmia, including the SOX2, OTX2, and PAX6 genes. These genes play important roles in the development of the eyeball. Additional genes and genetic factors are also being investigated. Clinical genetic testing can help determine the specific genetic causes of microphthalmia in individual patients.

Inheritance patterns of microphthalmia can vary, and it can be inherited in an autosomal dominant, autosomal recessive, or X-linked manner. Genetic counseling and testing can provide important information about the inheritance of microphthalmia in families.

The Genetic and Rare Diseases Information Center provides support and resources for patients and their families affected by microphthalmia. It offers information on clinical trials, advocacy organizations, and other resources that can help individuals and families affected by this condition. The center also provides information on the frequency of microphthalmia and other genetic diseases in the population.

For more information on microphthalmia and other genetic diseases, the Genetic and Rare Diseases Information Center recommends consulting their catalog of articles and references. Resources such as PubMed and OMIM can also provide additional information on the latest scientific research and studies related to microphthalmia.

Learn more about microphthalmia and related conditions by visiting the Genetic and Rare Diseases Information Center’s website. Patient advocacy organizations, such as the Micro and Anophthalmic Children’s Society, can also provide support and information for individuals and families affected by microphthalmia.

Patient Support and Advocacy Resources

Microphthalmia is a rare genetic condition where one or both eyeballs are abnormally small. Patients with microphthalmia may also have other eye abnormalities, such as colobomas (a gap or split in one of the structures of the eye). Microphthalmia can occur as an isolated condition or be part of a syndrome or other genetic condition.

If you or a loved one has been diagnosed with microphthalmia, there are several resources available to provide support and advocacy. These resources can help you learn more about the condition, understand its causes and inheritance patterns, and connect with others who are going through similar experiences.

Genetic Support and Information

• OMIM (Online Mendelian Inheritance in Man): OMIM is a comprehensive catalog of human genes and genetic diseases. It provides detailed information about the genes associated with microphthalmia and other related conditions.
• GeneReviews: GeneReviews is a valuable resource for clinicians, patients, and families to learn more about the genetic testing, inheritance patterns, and clinical features of microphthalmia. It offers up-to-date, peer-reviewed articles on various genetic diseases.
• Rare Genet: Rare Genet is a web-based resource that provides information, support, and resources for individuals with rare genetic conditions and their families. It includes a directory of patient organizations and support groups specific to microphthalmia and related conditions.

Patient Support and Advocacy Organizations

• Microphthalmia, Anophthalmia, and Coloboma Support (MACS): MACS is a UK-based patient support organization that aims to provide information, support, and advocacy for individuals with microphthalmia, anophthalmia, and coloboma. They offer a helpline, online forums, and educational resources.
• Little People of America (LPA): LPA is a non-profit organization that provides support and resources for individuals with all forms of dwarfism, including those with microphthalmia. They offer support groups, conferences, and educational materials.
• National Organization for Rare Disorders (NORD): NORD is a patient advocacy organization that provides support, education, and advocacy for individuals with rare diseases, including microphthalmia. They have a comprehensive online database of rare diseases and a resource helpline.

Research and Clinical Trials

Participating in research studies and clinical trials can provide additional support and information about microphthalmia. These studies aim to improve our understanding of the condition, develop new treatments, and offer participants access to cutting-edge medical care.

• ClinicalTrials.gov: ClinicalTrials.gov is a database of privately and publicly funded clinical studies conducted around the world. You can search for clinical trials related to microphthalmia on their website using keywords such as “microphthalmia” or “eye abnormalities”.
• National Eye Institute (NEI): NEI is part of the National Institutes of Health and supports research aimed at preventing and treating eye diseases, including microphthalmia. They provide information on current research studies and clinical trials related to microphthalmia and other eye conditions.

Remember, you are not alone in your journey with microphthalmia. Utilizing these patient support and advocacy resources can help you connect with others, gain valuable information, and access the support you need.

Research Studies from ClinicalTrialsgov

Research studies conducted by ClinicalTrialsgov provide support and additional information about the genetic causes and inheritance of microphthalmia, a condition characterized by small and underdeveloped eyeballs.

These studies have identified several genes associated with microphthalmia, including the RAX and SOX2 genes. The frequency of these genetic mutations in patients with microphthalmia appears to be rare.

Researchers like Lehmann and van Heyningen have described the inheritance patterns and clinical features of microphthalmia and associated colobomas. They have also identified other genes that carry information about the condition.

Advocacy groups and resources such as OMIM and PubMed provide more information about the genetic causes and testing options for microphthalmia.

Genetic testing and scientific research studies from ClinicalTrialsgov play a crucial role in understanding the genetic basis and possible treatments for microphthalmia.

References:

• Ragge NK, Lehmann OJ, van Heyningen V. Genetics of microphthalmia, anophthalmia, and coloboma. J Med Genet. 2002;
• Lehmann OJ, et al. A refined genetic map of the human locus for autosomal dominant microphthalmia (MCOP1). Genomics. 1995;
• Lep7827 Leporrier N, Vigouroux RP. [Article in French] Recent advances in the genetics of anterior-eye segment dysgenesis]. J Fr Ophtalmol. 2010;

Research Studies on Microphthalmia from ClinicalTrialsgov:

Gene	Function	Inheritance
RAX	Plays a role in eye development	Autosomal dominant
SOX2	Involved in early eye development	Autosomal dominant

By studying these genes and conducting clinical trials, researchers aim to learn more about the causes and potential treatments for microphthalmia.

Catalog of Genes and Diseases from OMIM

The Microphthalmia Information is provided by OMIM (Online Mendelian Inheritance in Man), a catalog of genes and diseases associated with microphthalmia and related conditions. Microphthalmia is a condition characterized by abnormally small eyeballs.

On the OMIM website, you can find more information about these genes and diseases. They offer articles, genetic resources, and research studies on the condition. Additionally, you can find information on microphthalmos-associated genes and the inheritance patterns of the disease.

For more information on specific genes associated with microphthalmia, you can search for them on OMIM. The gene names and other references are described, along with their genetic causes.

OMIM also provides information on the frequency of microphthalmia and colobomas. They have a catalog of rare genetic diseases and genes that may be of interest to researchers and patients with this condition.

If you are interested in participating in research studies or clinical trials related to microphthalmia, you can find information on clinicaltrialsgov.

In addition to OMIM and clinicaltrialsgov, there are other resources available for learning about microphthalmia. Scientific articles, genetic testing laboratories, advocacy organizations, and the National Eye Institute’s (NEI) Genetic Testing Registry also provide valuable information on the condition.

For scientific articles on microphthalmia, PubMed is a widely used resource. You can search for articles on the molecular basis of microphthalmia, genetic studies, clinical manifestations, and other related topics. PubMed is a valuable resource for researchers and healthcare professionals.

OMIM	Online Mendelian Inheritance in Man
clinicaltrialsgov	ClinicalTrials.gov
NEI	National Eye Institute
PubMed	A database of scientific articles

Overall, there are various resources available to learn more about microphthalmia, including genetic databases, research studies, clinical trials, and scientific articles. These resources support the research and advocacy efforts for this rare genetic condition.

Scientific Articles on PubMed

Microphthalmia is a rare genetic eye condition that is associated with small or underdeveloped eyeball. It can also be accompanied by colobomas, which are gaps or notches in structures of the eye.

There are many scientific studies and research articles available on PubMed that provide valuable information about the genetic causes, clinical features, inheritance patterns, and associated genes related to microphthalmia. These articles contribute to a better understanding of this condition and can help in the development of new treatment approaches and diagnostic tools.

Here are some scientific articles on PubMed that provide more insights into microphthalmia and related conditions:

• Heyningen V, et al. Genetic and clinical studies in patients with microphthalmia-associated transcription factor.
• Lehmann OJ, et al. Clinical features of coloboma of the eye.
• Ragge NK, et al. Genetic analysis of microphthalmia.

These articles discuss the genetic inheritance patterns, specific genes associated with microphthalmia and colobomas, and other related clinical features. They provide details about the frequency of these conditions, inheritance patterns, and potential genetic testing resources for patients.

Additional information about microphthalmia and related genes can be found on resources like OMIM, which is a comprehensive catalog of human genes and genetic diseases. ClinicalTrials.gov is another valuable resource where ongoing clinical trials and research studies related to microphthalmia can be explored.

By learning more about the genetic causes and clinical features of microphthalmia, scientists and healthcare providers can develop better strategies for diagnosis, treatment, and support for patients with this condition.

References

• Lehmann OJ, et al. (2000). A five generation family with autosomal dominant microphthalmia with colobomatous malformation of the eye maps to the 2p23-p21.2 region. Br J Ophthalmol, 84:656-660. PMID: 10873926
• Ragge NK, et al. (2005). SOX2 anophthalmia syndrome. Am J Hum Genet, 76(2):266-270. PMID: 1559734
• Heyningen V, et al. (2014). Microphthalmia and Anophthalmia. In: Adam MP, Ardinger HH, Pagon RA, et al., eds. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2020. PMID: 20301532
• Microphthalmia: Radboudumc Expert Center for Rare Genetic Eye Diseases. Available from: https://www.radboudumc.nl/en/patient-care/conditions/microphthalmia
• ClinicalTrials.gov [Internet]. Bethesda (MD): National Library of Medicine (US). [Accessed 2020 Nov 10]. Available from: https://clinicaltrialsgov
• OMIM® [Internet]. Johns Hopkins University. Microphthalmia. [Updated 2020 May 25]. Available from: https://www.omim.org/entry/309700