Rhizomelic chondrodysplasia punctata

Rhizomelic chondrodysplasia punctata is a rare developmental brain disorder characterized by abnormally short arms and legs (rhizomelia), seizures, recurrent respiratory tract infections and congenital cataracts.

Rhizomelic chondrodysplasia punctata
Low levels of plasmalogens is a characteristic of rhizomelic chondrodysplasia punctata.
SpecialtyMedical genetics Edit this on Wikidata
SymptomsAlopecia, flat face[1]
CausesPEX7 gene, GNPAT gene and AGPS gene mutations[2]
Diagnostic methodClinical and radiologic finding[3]
TreatmentPhysical therapy[4]

The cause is a genetic mutation that results in low levels of plasmalogens, which are a type of lipid found in cell membranes throughout the body, but whose function is not known.[2]

Signs and symptoms

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Rhizomelic chondrodysplasia punctata has the following symptoms:[4][1]

Genetics

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This condition is a consequence of mutations in the PEX7 gene, the GNPAT gene (which is located on chromosome 1) or the AGPS gene. The condition is acquired in an autosomal recessive manner.[2]

Pathophysiology

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ACAA1

The mechanism of rhizomelic chondrodysplasia punctata in the case of type 1 of this condition involves a defect in PEX7, whose product is involved in peroxisome assembly. There are 3 pathways that depend on peroxisomal biogenesis factor 7 activities, including:[4][5][verification needed]

  • AGPS (catalyzes plasmalogen biosynthesis)
  • PhYH (catalyzes catabolism of phytanic acid)
  • ACAA1 (catalyzes beta-oxidation of VLCFA - straight)

Diagnosis

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Peroxisome (this condition affects the peroxisome, causing peroxisome biogenesis disorders.)

The diagnosis of rhizomelic chondrodysplasia punctata can be based on genetic testing[6] as well as radiography results, plus a physical examination of the individual.[3]

Types

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Treatment

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Management of rhizomelic chondrodysplasia punctata can include physical therapy; additionally orthopedic procedures improved function sometimes in affected people.[4]

Prognosis

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The prognosis is poor in this condition,[3] and most children die before the age of 10.[4] However, some survive to adulthood, especially if they have a non-classical (mild) form of RCDP.[4]

Children with classical, or severe, RCDP1 have severe developmental disabilities. Most of them achieve early developmental skills, such as smiling, but they will not develop skills expected from a baby older than six months (such as feeding themselves or walking).[4] By contrast, children with non-classical mild RCDP1 often learn to walk and talk.[4]

See also

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References

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  1. ^ a b "Rhizomelic chondrodysplasia punctata type 1". Genetic and Rare Diseases Information Center (GARD) – an NCATS Program. US National Library of Medicine. Archived from the original on 24 January 2017. Retrieved 23 January 2017.
  2. ^ a b c Reference, Genetics Home. "rhizomelic chondrodysplasia punctata". Genetics Home Reference. Archived from the original on 2016-12-24. Retrieved 2017-01-16.
  3. ^ a b c "Rhizomelic chondrodysplasia punctata". Orphanet. Archived from the original on 2 February 2017. Retrieved 23 January 2017.
  4. ^ a b c d e f g h i Braverman, Nancy E.; Moser, Ann B.; Steinberg, Steven J. (2020). "Rhizomelic Chondrodysplasia Punctata Type 1". GeneReviews. PMID 20301447. NBK1270. Archived from the original on 2017-01-18. Retrieved 2017-01-16.
  5. ^ Brodsky, Michael C. (2016-06-28). Pediatric Neuro-Ophthalmology. Springer. p. 620. ISBN 9781493933846. Archived from the original on 2023-01-11. Retrieved 2020-11-21.
  6. ^ "Rhizomelic chondrodysplasia punctata type 1". Genetics Testing Laboratory (GTR): Conditions. US National Library of Medicine. Archived from the original on 8 February 2017. Retrieved 23 January 2017.
  7. ^ Online Mendelian Inheritance in Man (OMIM): Rhizomelic Chondrodysplasia Punctata, Type 2; RCDP2 - 222765
  8. ^ Online Mendelian Inheritance in Man (OMIM): Rhizomelic Chondrodysplasia Punctata, Type 3; RCDP3 - 600121

Further reading

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