• Source: Ring chromosome 14 syndrome

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 – thus forming a ring chromosome. It causes a number of serious health issues.




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:

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




Cause



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).
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; while once born, one can do the following to ascertain a diagnosis of the condition:

MRI
EEG




Management



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.




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.




See also


Ring chromosome 18 syndrome
Ring chromosome 20 syndrome




References






Further reading


Disorders, National Organization for Rare (2003-01-01). NORD Guide to Rare Disorders. Lippincott Williams & Wilkins. ISBN 9780781730631.
Zollino M.; Seminara L.; Orteschi D.; Gobbi G.; Giovannini S.; Della Giustina E.; Frattini D.; Scarano A.; Neri G. (2009). "The Ring14 Syndrome: Clinical and Molecular Definition" (PDF). American Journal of Medical Genetics. 149A (6): 1116–1124. doi:10.1002/ajmg.a.32831. PMID 19441122. S2CID 22919033.




External links

Kata Kunci Pencarian:

• Rabun jauh
• Sitoskeleton prokariotik
• Ring chromosome 14 syndrome
• Ring chromosome
• Turner syndrome
• Chromosome abnormality
• List of syndromes
• Angelman syndrome
• Myelodysplastic syndrome
• Chromosome 21
• Down syndrome
• Miller–Dieker syndrome