Which are the causes of Ring Chromosome 14 Syndrome?

TL;DR: Ring Chromosome 14 Syndrome is a rare chromosomal disorder caused by the formation of a ring structure in chromosome 14, typically resulting from the loss (deletion) of genetic material at the ends of the chromosome. This structural abnormality disrupts normal development and is usually a random, "de novo" event rather than an inherited trait passed down from parents.

What causes Ring Chromosome 14 Syndrome?

The primary cause of Ring Chromosome 14 Syndrome is a structural chromosomal aberration. During cell division, the two ends of chromosome 14 break off and the remaining part of the chromosome fuses together to form a ring shape. Because the tips of the chromosome (the telomeres) are lost during this process, the individual lacks essential genetic information required for normal neurological and physical development.

Is Ring Chromosome 14 Syndrome hereditary?

In the vast majority of cases, Ring Chromosome 14 Syndrome is not inherited. It is considered a de novo (new) mutation, meaning it occurs spontaneously during the formation of reproductive cells (eggs or sperm) or very early in embryonic development. Parents of a child with Ring Chromosome 14 Syndrome typically have normal chromosomes, and the risk of having another child with this condition is very low.

Are there specific genetic factors involved?

The clinical severity of Ring Chromosome 14 Syndrome is often linked to the specific amount of genetic material lost during the ring formation. Researchers focus on several key areas:

• Terminal Deletions: The loss of genes located near the 14q32 region, which is critical for brain development and immune system function.


• Ring Instability: The ring chromosome may be unstable during cell division, leading to "mosaicism," where some cells have the ring while others lose the chromosome entirely.


• Gene Dosage Effect: Because the body requires two functional copies of most genes, the deletion on the ring chromosome creates an imbalance that disrupts cellular signaling.

What is the current state of research?

While the structural cause of Ring Chromosome 14 Syndrome is well-identified via karyotyping or chromosomal microarray analysis, scientists are still researching how these specific deletions manifest as epilepsy and intellectual disability. Current studies are investigating the role of the AKT1 gene and other nearby loci to better understand the pathophysiology of Ring Chromosome 14 Syndrome.

Next steps

• Consult with a clinical geneticist for a detailed chromosomal microarray analysis.


• Connect with the 22 members currently sharing experiences with Ring Chromosome 14 Syndrome on DiseaseMaps.org.


• Seek a referral to a neurologist specializing in rare genetic epilepsy syndromes.

Medical disclaimer: This information is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases (GARD) Information Center: Ring Chromosome 14 Syndrome.


• Orphanet: Ring chromosome 14 syndrome (ORPHA:1425).


• OMIM (Online Mendelian Inheritance in Man): Chromosome 14, ring.


• Ring14 International: Patient advocacy and research foundation.