Medicine:Ring chromosome 14 syndrome

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Ring chromosome 14 syndrome
Other namesRing 14, Ring chromosome 14
NLM ring chromosome.jpg
Formation of a ring chromosome.
SymptomsSeizures, intellectual disability[1]
CausesCaused by a chromosomal abnormality[1]
Diagnostic methodMRI, EEG[2]
TreatmentAnticonvulsive medication[2]

Ring chromosome 14 syndrome is a very rare human chromosome abnormality. It occurs when one or both of the telomeres that mark the ends of chromosome 14 are lost allowing the now uncapped ends to fuse together forming a ring chromosome. It causes a number of serious health issues.[1][3][4]

Symptoms and signs

The most common symptoms are intellectual disability and recurrent seizures developing in infancy or early childhood. Typically the seizures are resistant to treatment with anti-epileptic drugs. Other symptoms may include:[1][5]

  • Microcephaly
  • Lymphedema
  • Facial abnormalities
  • Immune deficiencies
  • Abnormalities of retina
  • Slow growth
  • Short stature

Cause

Telomer-structure
Chr 14

The syndrome is caused by the loss of genetic material near the end of the long arm (q) of chromosome 14 . The break that causes the telomere(s) to be lost occurs near the end of the chromosome, and is called a constitutional ring. These rings arise spontaneously ( it is rarely inherited).[4][1][6][2]

The genetic abnormality occurs randomly in sperm or egg cells or it may occur in early embryonic growth, if it occurs during embryonic growth the ring chromosome may be present in only some of a person's cells.

Diagnosis

Diagnosis is achieved by examining the structure of the chromosomes through karyotyping;[7] while once born, one can do the following to ascertain a diagnosis of the condition:[2]

  • MRI
  • EEG

Management

[8] A type of anticonvulsant(Carbamazepine)

In terms of the management of ring chromosome 14 syndrome, anticonvulsive medication for seizures, as well as, proper therapy to help prevent respiratory infections in the affected individual are management measures that can be taken.[2]

Epidemiology

Ring chromosome 14 syndrome is extremely rare, the true rate of occurrence is unknown (as it is less than 1 per 1,000,000), but there are at least 50 documented cases in the literature.[9]

See also

References

  1. 1.0 1.1 1.2 1.3 1.4 Reference, Genetics Home. "ring chromosome 14 syndrome" (in en). https://ghr.nlm.nih.gov/condition/ring-chromosome-14-syndrome#resources. 
  2. 2.0 2.1 2.2 2.3 2.4 Disorders, National Organization for Rare (2003) (in en). NORD Guide to Rare Disorders. Lippincott Williams & Wilkins. p. 64. ISBN 9780781730631. https://books.google.com/books?id=99YPDvFWBB0C&q=Ring+chromosome+14+syndrome+nih&pg=PA64. 
  3. "Chromosome Abnormalities Fact Sheet". https://www.genome.gov/11508982/. 
  4. 4.0 4.1 "OMIM Entry - # 616606 - RING CHROMOSOME 14 SYNDROME" (in en-us). https://omim.org/entry/616606. 
  5. Zollino, Marcella; Ponzi, Emanuela; Gobbi, Giuseppe; Neri, Giovanni (2012-05-01). "The ring 14 syndrome". European Journal of Medical Genetics 55 (5): 374–380. doi:10.1016/j.ejmg.2012.03.009. ISSN 1878-0849. PMID 22564756.  – via ScienceDirect (Subscription may be required or content may be available in libraries.)
  6. Kelly, Evelyn B. (2013-01-07) (in en). Encyclopedia of Human Genetics and Disease. ABC-CLIO. p. 729. ISBN 9780313387135. https://books.google.com/books?id=gqMYt17klVIC&q=Ring+chromosome+14+syndrome++telomeres&pg=PA729. 
  7. "Ring chromosome 14 - Conditions - GTR - NCBI" (in en). https://www.ncbi.nlm.nih.gov/gtr/conditions/C2930916/. 
  8. Wallace, Sheila J.; Farrell, Kevin (2004-02-27) (in en). Epilepsy in Children, 2E. CRC Press. p. 354. ISBN 9780340808146. https://books.google.com/books?id=kKtiW-wTPh4C&q=Ring+chromosome+14+syndrome++Carbamazepine&pg=PA354. 
  9. RESERVED, INSERM US14 -- ALL RIGHTS. "Orphanet: Ring chromosome 14" (in en). http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=1440. 

Further reading

External links

Classification
External resources