biology

Lamb–Shaffer syndrome

Lamb–Shaffer 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 Lamb–Shaffer syndrome rather than just read about it. In short: Lamb–Shaffer syndrome is a rare autosomal dominant genetic condition. Less than 40 cases have been reported by 2018.

Key takeaways

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

Reference excerpt

Lamb–Shaffer syndrome is a rare autosomal dominant genetic condition. Less than 40 cases have been reported by 2018.

Signs and symptoms Clinical features include

Global developmental delay Significant speech delay Hypotonia Micrognathia Scoliosis Defects in motor function, both fine and gross Optic atrophy Oculomotor apraxia Strabismus Frontal bossing Ear abnormalities Low nasal bridge Epicanthal folds Midline tongue groove

Genetics This condition is caused by mutations in the SRY-related HMG-box (SOX5) gene. This gene encodes a protein in the family of transcription factors involved in embryonic and cellular development. The gene is located on the short arm of chromosome 12 (12p12). A study published in 2019 examining 34 families shows that 74% (25/34 families) of cases of the condition are likely to be of de novo occurrence, as the variants could not be detected in parental blood samples. In 15% (5/34 families) of the patients, the condition was likely inherited from a mosaic parent. In 3% (1/34), the condition was inherited from an affected parent. This means that the majority of the patients have parents who are unaffected whereas inheritance is also possible.

Pathogenesis It is unclear how this mutation causes the clinical picture.

Diagnosis The diagnosis may be suspected based on the constellation of clinical features, but may only be determined by a genetic test. The full exome sequencing test determines the partial deletion, deletion, or mutation to the SOX5 gene. It is made by sequencing the SOX5 gene responsible for the cells that facilitate information transfer in the brain. Symptoms of Lamb-Shaffer syndrome include fine and gross motor delays, speech delay, global developmental delay, hypotonia, and vision issues, commonly misdiagnosed as an autism spectrum disorder.

Treatment There is currently no curative treatment for this condition. Supportive management is all that is currently available.

Epidemiology This is a rare condition with a prevalence of < 1/106. The total number of cases reported to date is <550.

History This condition was first described by Lamb et al in 2012.

References

Illustrations

Worked examples

Example 1 — a first encounter with Lamb–Shaffer syndrome

Start with the simplest possible case. Write down what Lamb–Shaffer 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 Lamb–Shaffer 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 Lamb–Shaffer 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 Lamb–Shaffer syndrome

In research: Lamb–Shaffer 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 Lamb–Shaffer 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: Lamb–Shaffer syndrome is common in secondary-school and first-year university syllabi. It links to neighbouring topics Autosomal dominant disorders, Genetic syndromes, Rare diseases, so understanding it makes those chapters shorter.
In everyday life: Look for Lamb–Shaffer 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 Lamb–Shaffer syndrome in 20 minutes

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

Frequently asked questions

What is Lamb–Shaffer syndrome in simple terms?

Lamb–Shaffer syndrome is a rare autosomal dominant genetic condition. Less than 40 cases have been reported by 2018.

Why does Lamb–Shaffer 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 Lamb–Shaffer 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 Lamb–Shaffer syndrome.