biology

Microphthalmia, syndromic 12 (MCOPS12)

Microphthalmia, syndromic 12 (MCOPS12) is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Microphthalmia, syndromic 12 (MCOPS12) rather than just read about it. In short: Microphthalmia, syndromic 12 (MCOPS12) is an ultra-rare and complex neurological disease. It is caused by a single-point missense mutation in the retinoic acid receptor beta (RARB) gene.

Key takeaways

Microphthalmia, syndromic 12 (MCOPS12) belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Microphthalmia, syndromic 12 (MCOPS12) to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Microphthalmia, syndromic 12 (MCOPS12) from memory before moving on to harder problems.

Reference excerpt

Microphthalmia, syndromic 12 (MCOPS12) is an ultra-rare and complex neurological disease. It is caused by a single-point missense mutation in the retinoic acid receptor beta (RARB) gene. The most common disease symptoms are microphthalmia, severe (progressive) movement disorders and intellectual disability. Movement disorders may include spasticity, dystonia and chorea. In addition, malformations such as incomplete lung development (pulmonary hypoplasia), defects of the cerebellum (Chiari type I malformation), and a defect/hole in the diaphragm (diaphragmatic hernia) have been observed.

Gene The retinoic acid receptor beta (RARB) gene (Gene ID: 5915) is located on the short (p) arm of chromosome 3 (3p24.2). It consists of 13 exons, four promoter regions and has a size of 423 kb in humans. RARB encodes retinoic acid receptor beta (RAR-beta), which belongs to the retinoic acid receptor family together with the other sub-types RAR-alpha and RAR-gamma. Several variations of the single point mutation have been identified, with mutation c.1159C>T (p.R387C) being most prominent (i.e. cytosine is replaced by thymine in nucleotide 1159 causing arginine (R) at amino acid position 387 to be replaced by cysteine (C) in RAR-beta). The respective variant impacts the disease phenotype, thus leading to heterogenous characteristics of the disease depending on the variant of the mutation. RAR-beta is a nuclear receptor and transcription factor. Upon activation by retinoic acid (the biologically active form of vitamin A), it regulates the expression of a plethora of genes in the human body. It plays a pivotal role in the development of the embryonic digestive tract, eye, myogenesis, and brain (especially the striatum). Furthermore, RAR-beta is a tumor suppressor and hence has been in the focus of cancer therapy for almost two decades.

Research Mutations in the RAR-beta protein lead to MCOPS12 with pleiotropic defects of an unknown cause. The mutations in RAR-beta most likely result in conformational changes of the receptor’s ligand binding domain, hence to altered ligand binding and transcriptional activity of the receptor. These could be loss of function, reduction in function, or gain of normal function. Movement disorders are typically explained by some dysfunction in the striatum, which forms a critical part of the motor control system in the brain. Information input comes from the hindbrain by dopaminergic neurons, which connect to medium spiny neurons (MSN) in the striatum. The striatum contains two distinct types of MSNs (D1R and D2R) that carry information to different brain regions. Both D1R and D2R are dopamine receptors. RAR-beta is a transcription factor and the D2R dopamine receptor is one of its targets. It is hypothesized that changes in RAR-beta transcriptional activity change MSN gene expression, protein composition, and metabolic activity thus leading to the observed neurological disorders. The RAinRARE consortium federates research teams from four academic institutions to establish disease models and determine the mechanism through which mutant forms of RAR-beta affect striatum functions. Ultimately, the consortium aims to develop therapeutic approaches for MCOPS12 and robust biomarkers for monitoring the efficiency of these approaches. The teams have obtained funding by the European Union via the E-Rare platform to support this research program.

Patient advocacy Cure MCOPS12 is a non-profit organization which was established in 2020 in Austria. Its mission is to raise awareness and fundraising to support scientific research and clinical development that will ultimately result in a cure. Amongst others, Cure MCOPS12 has funded a Natural History Study for MCOPS12 patients, which is scheduled to start in 2021.

References

External links RARB retinoic acid receptor beta RARB Gene (protein coding) Microphthalmia with or without pulmonary hypoplasia, diaphragmatic hernia, and/or cardiac defects

Worked examples

Example 1 — a first encounter with Microphthalmia, syndromic 12 (MCOPS12)

Start with the simplest possible case. Write down what Microphthalmia, syndromic 12 (MCOPS12) claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Microphthalmia, syndromic 12 (MCOPS12) before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Microphthalmia, syndromic 12 (MCOPS12) ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Microphthalmia, syndromic 12 (MCOPS12)

In research: Microphthalmia, syndromic 12 (MCOPS12) appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Microphthalmia, syndromic 12 (MCOPS12) in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Microphthalmia, syndromic 12 (MCOPS12) is common in secondary-school and first-year university syllabi. It links to neighbouring topics Neurological disorders, so understanding it makes those chapters shorter.
In everyday life: Look for Microphthalmia, syndromic 12 (MCOPS12) outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Microphthalmia, syndromic 12 (MCOPS12) in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Microphthalmia, syndromic 12 (MCOPS12) means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Microphthalmia, syndromic 12 (MCOPS12) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Microphthalmia, syndromic 12 (MCOPS12) in simple terms?

Microphthalmia, syndromic 12 (MCOPS12) is an ultra-rare and complex neurological disease. It is caused by a single-point missense mutation in the retinoic acid receptor beta (RARB) gene.

Why does Microphthalmia, syndromic 12 (MCOPS12) matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Microphthalmia, syndromic 12 (MCOPS12)?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Microphthalmia, syndromic 12 (MCOPS12).