biology

Tatton-Brown–Rahman syndrome

Tatton-Brown–Rahman syndrome 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 Tatton-Brown–Rahman syndrome rather than just read about it. In short: Tatton-Brown–Rahman syndrome (TBRS) is a rare overgrowth and intellectual disability syndrome caused by autosomal dominant mutations in the DNMT3A gene. The syndrome was first recognized in 2014 by Katrina Tatton-Brown, Nazneen Rahman, and collaborators.

Key takeaways

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

Reference excerpt

Tatton-Brown–Rahman syndrome (TBRS) is a rare overgrowth and intellectual disability syndrome caused by autosomal dominant mutations in the DNMT3A gene. The syndrome was first recognized in 2014 by Katrina Tatton-Brown, Nazneen Rahman, and collaborators.

Signs and symptoms TBRS is defined by overgrowth and mild-to-severe intellectual disability. All individuals with TBRS experience some degree of developmental delay and/or intellectual disability, with 86% of well-documented cases falling in the mild to moderate range. Most individuals with TBRS exhibit increased stature, head circumference, and weight at least two standard deviations above the mean. Generalized joint hypermobility and hypotonia are observed in ~75% and ~55% of cases, respectively, and are often associated with musculoskeletal pain and joint instability. Approximately half of individuals exhibit behavioral or psychiatric issues; the most common diagnosis is autism spectrum disorder. Febrile seizures and afebrile seizures have been reported in ~20% of individuals with TBRS. The facial gestalt of TBRS includes a round face; thick, horizontal, low-set eyebrows; vertically narrow palpebral fissures; and prominent maxillary central incisors. These features often become most clinically recognizable in adolescence. Congenital heart defects and aortic root dilatation have been observed in ~10% of cases. Approximately 20% of males with TBRS have cryptorchidism. Vesicoureteral reflux and hypospadias have been reported in some cases. Neuroimaging findings may include corpus callosum anomalies, small posterior cranial fossa, asymmetric arcuate and uncinate fasciculi, deep left Sylvian fissure, and increased cortical thickness

Cause TBRS is caused by autosomal dominant mutations in the DNMT3A gene. Nearly all cases are caused by de novo mutations; rarely, a pathogenic variant can be inherited from an affected parent or an unaffected mosaic parent. DNMT3A overgrowth mutations are hypothesized to interfere with the enzyme's role in H3K36me2-regulated non-CpG DNA methylation.

Management and prognosis The majority of individuals with TBRS are in good health. An individual's specific features are treated and managed as indicated. Early childhood intervention and special education (IFSP and IEP in the United States) are recommended. Because DNMT3A mutations are commonly observed in acute myeloid leukemia, TBRS may be associated with increased cancer risk.

See also Overgrowth syndrome Sotos syndrome Weaver syndrome

References

External links

Worked examples

Example 1 — a first encounter with Tatton-Brown–Rahman syndrome

Start with the simplest possible case. Write down what Tatton-Brown–Rahman syndrome 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 Tatton-Brown–Rahman syndrome 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 Tatton-Brown–Rahman syndrome 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 Tatton-Brown–Rahman syndrome

In research: Tatton-Brown–Rahman syndrome 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 Tatton-Brown–Rahman syndrome 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: Tatton-Brown–Rahman syndrome is common in secondary-school and first-year university syllabi. It links to neighbouring topics Autosomal dominant disorders, Medical conditions related to obesity, Rare genetic syndromes, so understanding it makes those chapters shorter.
In everyday life: Look for Tatton-Brown–Rahman syndrome 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Tatton-Brown–Rahman syndrome” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Tatton-Brown–Rahman syndrome in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Tatton-Brown–Rahman syndrome 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 Tatton-Brown–Rahman syndrome out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Tatton-Brown–Rahman syndrome in simple terms?

Why does Tatton-Brown–Rahman syndrome 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 Tatton-Brown–Rahman syndrome?

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 Tatton-Brown–Rahman syndrome.