biology

PLAID syndrome

PLAID 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 PLAID syndrome rather than just read about it. In short: PLAID syndrome is an inherited condition characterised by antibody deficiency and immune dysregulation, first described in 2012. The name is an acronym of "PLCG2-associated antibody deficiency and immune dysregulation".

Key takeaways

PLAID 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 PLAID syndrome to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PLAID syndrome from memory before moving on to harder problems.

Reference excerpt

PLAID syndrome is an inherited condition characterised by antibody deficiency and immune dysregulation, first described in 2012. The name is an acronym of "PLCG2-associated antibody deficiency and immune dysregulation". It is characterised by cold-induced urticaria, autoimmunity, atopy and humoral immune deficiency.

Presentation This condition is characterised by cold induced urticaria, autoimmunity, atopy and humoral immune deficiency. The humeral immune deficiency results in recurrent bronchopulmonary infections. Cutaneous granulomas may also occur. The urticaria usually appears within 12 months of birth but may appear immediately after birth. Swallowing cold materials may be associated with discomfort. Autoimmune thyroiditis and vitiligo may occur. Recurrent infections may lead to the development of bronchiectasis.

Genetics The syndrome is caused by mutations in the phospholipase C gamma 2 (PLCG2) gene. This gene is located on the long arm of chromosome 16 (16q23.3). The pathogenesis of this condition is not understood. It is however known that phospholipase C gamma is an important signalling mediation for natural killer cells.

Diagnosis Two thirds of patients have positive anti nuclear antibodies. The IgM levels are usually low and a low IgA is common. There is a poor antibody response to pneumococcal vaccines. The natural killer cells are low or low normal. Switched memory B cells (IgM, IgD, CD27+) may be present in the blood.

Differential diagnosis Familial cold urticaria

Epidemiology This is considered a rare condition, with 30 patients described in the literature up to 2019.

History This condition was first described in 2012. The name is an acronym of PLCG2-associated antibody deficiency and immune dysregulation.

References

Further reading Ombrello, MJ; et al. (26 January 2012). "Cold urticaria, immunodeficiency, and autoimmunity related to PLCG2 deletions". The New England Journal of Medicine. 366 (4): 330–8. doi:10.1056/NEJMoa1102140. PMC 3298368. PMID 22236196.

External links

Illustrations

Worked examples

Example 1 — a first encounter with PLAID syndrome

Start with the simplest possible case. Write down what PLAID 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 PLAID 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 PLAID 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 PLAID syndrome

In research: PLAID 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 PLAID 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: PLAID syndrome is common in secondary-school and first-year university syllabi. It links to neighbouring topics Genetic syndromes, Immune system disorders, so understanding it makes those chapters shorter.
In everyday life: Look for PLAID 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.

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How to study PLAID syndrome in 20 minutes

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

Frequently asked questions

What is PLAID syndrome in simple terms?

Why does PLAID 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 PLAID 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 PLAID syndrome.