science

X-linked recessive chondrodysplasia punctata

X-linked recessive chondrodysplasia punctata is a science 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 X-linked recessive chondrodysplasia punctata rather than just read about it. In short: X-linked recessive chondrodysplasia punctata is a type of chondrodysplasia punctata that can involve the skin, hair, and cause short stature with skeletal abnormalities, cataracts, and deafness. This condition is also known as arylsulfatase E deficiency, CDPX1, and X-linked recessive chondrodysplasia punctata 1.

Key takeaways

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

Reference excerpt

X-linked recessive chondrodysplasia punctata is a type of chondrodysplasia punctata that can involve the skin, hair, and cause short stature with skeletal abnormalities, cataracts, and deafness. This condition is also known as arylsulfatase E deficiency, CDPX1, and X-linked recessive chondrodysplasia punctata 1. The syndrome rarely affects females, but they can be carriers of the recessive allele. Although the exact number of people diagnosed with CDPX1 is unknown, it was estimated that 1 in 500,000 have CDPX1 in varying severity. This condition is not linked to a specific ethnicity. The mutation that leads to a deficiency in arylsulfatase L (ARSL) occurs in the coding region of the gene. Absence of stippling, deposits of calcium, of bones and cartilage, shown on x-ray, does not rule out chondrodysplasia punctata or a normal chondrodysplasia punctata 1 (CDPX1) gene without mutation. Stippling of the bones and cartilage is rarely seen after childhood. Phalangeal abnormalities are important clinical features to look for once the stippling is no longer visible. Other, more severe, clinical features include respiratory abnormalities, hearing loss, cervical spine abnormalities, delayed cognitive development, ophthalmologic abnormalities, cardiac abnormalities, gastroesophageal reflux, and feeding difficulties. CDPX1 actually has a spectrum of severity; different mutations within the CDPX1 gene have different effects on the catalytic activity of the ARSL protein. The mutations vary between missense, nonsense, insertions, and deletions.

Cause The only known cause of this condition is a mutation in the X-linked chondrodysplasia punctata 1 (CDPX1) gene. Mutations in this gene result in a deficiency of arylsulfatase L. Only 50-60% of cases have been shown to have mutations in this gene and the cause of the remaining cases is not yet known. The CDPX1 gene is located on the short arm of the X chromosome (Xp22.3) on the Crick (minus) strand. It is 33,614 bases in length.

The mature protein has a molecular weight of 68 kilodaltons. It is glycosylated and is located in the Golgi apparatus. Its activity may be inhibited by warfarin. It seems likely that warfarin induced embryotoxicity may be due at least in part to this inhibition. Brachytelephalangic chondrodysplasia punctata (BCDP) is the non-genetic, or environmentally produced, phenocopies associated with CDPX1. Causes of BCDP can also come from genetic effects, mainly due to mutations. Keutel syndrome, deficiency of vitamin K epoxide reductase subunit 1 (VKORC1), gamma-glutamyl carboxylase (GGCX), Xp contiguous deletion syndromes, and multiple sulfatase deficiency are all genetic conditions that are associated BCDP.

Diagnosis This condition occurs almost exclusively in males. The mutation may be spontaneous or inherited from the mother. The typical clinical features are:

flat nasal tip short columella maxillary hypoplasia involvement of terminal phalanges stippled chondrodystrophy

Biochemical confirmation The activity of arylsulfatase L can be measured with the substrate 4-methylumbelliferyl sulfate.

Treatment CDPX1 activity may be inhibited by warfarin because it is believed that ARSL has enzymatic activity in a vitamin K producing biochemical pathway. Vitamin K is also needed for controlling binding of calcium to bone and other tissues within the body.

See also List of cutaneous conditions List of radiographic findings associated with cutaneous conditions

References

External links

Worked examples

Example 1 — a first encounter with X-linked recessive chondrodysplasia punctata

Start with the simplest possible case. Write down what X-linked recessive chondrodysplasia punctata claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 X-linked recessive chondrodysplasia punctata 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 X-linked recessive chondrodysplasia punctata 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 X-linked recessive chondrodysplasia punctata

In research: X-linked recessive chondrodysplasia punctata appears in science 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 X-linked recessive chondrodysplasia punctata 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: X-linked recessive chondrodysplasia punctata is common in secondary-school and first-year university syllabi. It links to neighbouring topics Enzyme defects, Genodermatoses, X-linked recessive disorders, so understanding it makes those chapters shorter.
In everyday life: Look for X-linked recessive chondrodysplasia punctata 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 “X-linked recessive chondrodysplasia punctata” →

Affiliate

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

How to study X-linked recessive chondrodysplasia punctata in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what X-linked recessive chondrodysplasia punctata 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 X-linked recessive chondrodysplasia punctata out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is X-linked recessive chondrodysplasia punctata in simple terms?

Why does X-linked recessive chondrodysplasia punctata matter?

Because it connects several science 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 X-linked recessive chondrodysplasia punctata?

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 X-linked recessive chondrodysplasia punctata.