achondrogenesis type 2

{{Infobox medical condition (new)

| name = Achondrogenesis type 2

| image = Autosomal dominant - en.svg

| caption = Achondrogenesis type 2 has an autosomal dominant method of inheritance.

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| field = Medical genetics

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Achondrogenesis, type 2 is an uncommon skeletal dysplasia that is autosomal dominant and occurs at a frequency of approximately 0.2 per 100,000 births.{{cite journal | title=Taybi and Lachman's Radiology of Syndromes, Metabolic Disorders and Skeletal Dysplasias, 5th ed | journal=Radiology | volume=249 | issue=3 | date=2008 | issn=0033-8419 | doi=10.1148/radiol.2493082537 | pages=776}} Also known by the name Langer-Saldino achondrogenesis, it is one of the fatal short-limbed dwarfisms linked to structural mutations in type II collagen.{{cite journal | last=Saldino | first=Ronald M. | title=Lethal Short-Limbed Dwarfism: Achondrogenesis and Thanatophoric Dwarfism | journal=American Journal of Roentgenology | volume=112 | issue=1 | date=1971 | issn=0361-803X | doi=10.2214/ajr.112.1.185 | pages=185–197| pmid=5582025 }}

Typically, achondrogenesis type II manifests in the perinatal period as short stature, edema/hydropic look, narrow chest with pulmonary hypoplasia, severely short limbs (micromelia), and extraskeletal characteristics (e.g., flat midface, Pierre Robin sequence). Most of these babies are stillborn, delivered before their due date, or pass away from cardiorespiratory failure soon after delivery, meaning that they do not live to term.{{cite web | last1=Gregersen | first1=Pernille Axél | last2=Savarirayan | first2=Ravi | title=Type II Collagen Disorders Overview | publisher=University of Washington, Seattle | date=2019-04-25 | pmid=31021589 |url=https://www.ncbi.nlm.nih.gov/books/NBK540447/ | access-date=2024-02-25}}

Signs and symptoms

The characteristic features of achondrogenesis type 2 are short arms and legs, a tiny chest with short ribs, lung hypoplasia, a small chin, a prominent forehead, and an enlarged abdomen that may also include hydrops, and polyhydramnios.{{cite journal | last1=Dogan | first1=P | last2=Varal | first2=IG | last3=Gorukmez | first3=O | last4=Akkurt | first4=MO | last5=Akdag | first5=A | title=Achondrogenesis type 2 in a newborn with a novel mutation on the COL2A1 gene | journal=Balkan Journal of Medical Genetics | publisher=Walter de Gruyter GmbH | volume=22 | issue=1 | date=2019-06-01 | issn=1311-0160 | doi=10.2478/bjmg-2019-0001 | pages=89–94| pmid=31523626 | pmc=6714336 }}

Causes

Mutations in the COL2A1 gene can cause a number of skeletal abnormalities, including achondrogenesis type 2. Instructions for producing a protein that produces type II collagen are provided by this gene. Type II collagen molecule assembly is disrupted by mutations in the COL2A1 gene, impairing the normal development of bones and other connective tissues.{{cite web | title=Achondrogenesis: MedlinePlus Genetics | website=MedlinePlus | date=2015-03-01 |url=https://medlineplus.gov/genetics/condition/achondrogenesis/ | access-date=2024-02-26}}

Because achromogenesis type 2 is caused by a mutated gene that only needs one copy in each cell, it is regarded as an autosomal dominant disorder.

References

{{Reflist}}

Further reading

  • {{cite journal | last1=Maheshwari | first1=Saurabh | last2=Ingole | first2=Dilip | last3=Chatterjee | first3=Samar | last4=Rajesh | first4=Uddandam | last5=Anand | first5=Varun | title=A case report of achondrogenesis type II (Langer-Saldino achondrogenesis) | journal=Egyptian Journal of Radiology and Nuclear Medicine | volume=52 | issue=1 | date=2021 | issn=2090-4762 | doi=10.1186/s43055-021-00479-0 | doi-access=free | ref=none}}
  • {{cite journal | last1=Kobayashi | first1=Yukari | last2=Ito | first2=Yuki | last3=Taniguchi | first3=Kosuke | last4=Harada | first4=Kana | last5=Yamamura | first5=Michihiro | last6=Sato | first6=Taisuke | last7=Takahashi | first7=Ken | last8=Kawame | first8=Hiroshi | last9=Hata | first9=Kenichiro | last10=Samura | first10=Osamu | last11=Okamoto | first11=Aikou | title=Novel missense COL2A1 variant in a fetus with achondrogenesis type II | journal=Human Genome Variation | publisher=Springer Science and Business Media LLC | volume=9 | issue=1 | date=2022-11-15 | page=40 | issn=2054-345X | doi=10.1038/s41439-022-00218-5 | pmid=36376277 | ref=none| pmc=9663423 }}