By: Sofia Arreguin
Ring 14 and Epilepsy
What is Ring 14?
Defined as a rare genetic disorder, the ring 14 chromosome, or r(14), is depicted as an abnormal chromosome classified among the ring chromosome group. This group is commonly characterized as having a “ring-shaped” structure instead of the typical stick-like appearance, caused by the rearrangement of a chromosome within a cell (“Ring 14,” n.d.). Chromosomes have long arms (q) and short arms (p), and individuals diagnosed with ring 14 syndrome, or who have the ring 14 chromosome, experience deletions in both arms, resulting in the binding of both arms’ ends. This essentially forms a circle or ring shape, omitting a portion of chromosome genes and material. However, it is believed that the loss of material from the long arm is what produces the effects of r(14), since the loss of material from the short arm yields no damage, as there are similar materials available on other chromosomes (“Ring 14,” n.d.). Symptoms may appear as a result of this rare condition, such as unusual facial features, intellectual disability, ocular abnormalities, gastrointestinal issues, malnutrition, respiratory infections, and motor delays. Individuals with r(14) appear to be short, have microcephaly, or a small head, an oval face, a long, narrow skull shape, full cheeks, a broad forehead, a broad nasal bridge, swollen hands and feet from the buildup of lymph fluid, known as lymphedema, and flat feet. They also experience issues with learning and development in both motor and language skills. For example, children with r(14) may have trouble walking, with some achieving this skill at 2 to 3 years of age, while others never do. They also experience having low muscle tone, or hypotonia, hyperactivity, with a “good-natured” mood, a few aggressive outbursts, trouble gaining weight, and an increased risk of respiratory infections, and sometimes pneumonia, which would necessitate medical treatment. Although their vision may not be affected, their eyes tend to be crossed and contain yellow, white, and grey-colored spots within their retina. The most significant symptom present within r(14), however, is epilepsy.
Ring 14 Related Epilepsy
Although r (14) has not been fully understood or studied, one prominent detail discovered within individuals with the ring 14 chromosome is the experience of seizures as part of their symptoms, a major characteristic of epilepsy. Known as early-onset refractory epilepsy, these seizures occur frequently during the first months of a person’s life, during infancy, and early childhood, and are often resistant to anti-epileptic medications; considerably more difficult to handle. They are often associated with the regression of motor development, mental growth, and acquisition of language. The types of seizures may vary; for instance, a person may experience myoclonic seizures, involving the sudden contraction of muscles, conic seizures, involving muscle spasms, tonic seizures, depicted by stiffness of muscles, and tonic-clonic seizures, characterized by longer-lasting heightened rigidity and rapid muscle contractions (“Chromosome Ring 14,” 2009). Seizures may also appear when a person is waking up and falling asleep, occurring collectively in what is known as seizure clusters. These clusters are stretches of heightened neural activity within the brain that result in seizures that last for a day, and possibly more (Said, 2021). It may also include status epilepticus, seizures exceeding the duration of 5 minutes, which increases the likelihood of losing certain skills, such as language and motor skills. These seizures are relatively more harmful, or worse, and more frequent during the early years of childhood, but improve during adolescence, meaning they are less frequent, while rarely do they fade altogether.
Research and Treatment
Diagnosing r(14) can be done during pregnancy through the use of an ultrasound, chronic villus sampling (CVS), and amniocentesis. In using ultrasounds, chromosomal abnormalities can be detected within the fetus. CVS removes tissue from the placenta, while amniocentesis analyzes the fluid surrounding the fetus; with this technique, medical professionals are able to detect chromosome 14 rings within. (“Chromosome Ring 14,” 2009). The diagnosis can also be accomplished after birth through the examination of the infant’s bodily features and from evaluations or clinical tests. Such tests include genetic testing, electroencephalography (EEG), magnetic resonance imaging (MRI), and computed tomography (CT) scanning (“Ring 14 Chromosome,” n.d.). During genetic testing, the use of karyotype, or assessment of chromosomes, involves a tissue, blood, and saliva sample, which are taken under a microscope in the search for a ring chromosome. A chromosomal microarray test may also be administered, where missing or additional fragments of genetic material are discovered, allowing for a better interpretation of which genes, and how many, were deleted as a result of the ring chromosome. An EEG essentially records neural activity within the brain, an MRI uses magnetic waves to produce detailed images of slices of the brain, or cross-sectional images, and a CT scan employs the use of an X-ray to compute a 3-dimensional image of the brain.
Ring 14 chromosome is not typically passed down from parents, but happens during the development of reproductive cells, such as the sperm and egg, or of the fetus. A cure for this disorder had not yet been discovered, but there are certain treatments to help produce a better quality of life. In some situations where individuals are not resistant to anti-epileptic medications, the use of such antiseizure drugs can control and prevent the occurrence of seizures. Treatment from medical professionals is also highly recommended, including pediatricians, neurologists, cardiologists, orthopedists, who specialize in skeletal and muscle disorders, and physical therapists, to manage the specific symptoms of the patient (“Chromosome Ring 14,” 2009). For example, a pediatrician can help treat and prevent upper respiratory infections that are often a result of r(14), while an orthopedic can recommend certain physical therapies to help combat rigidity and stiffness in the patient’s muscles. Like many disorders and illnesses, early intervention is the best, especially to help the affected individual gain most of their abilities and strength.
Conclusion
Ring 14 chromosome is a disorder not well understood by the medical community, and more research should be done to produce more effective treatments. This disorder is generally caused by the rearrangement of chromosomes, specifically the 14th chromosome, causing it to form a ring, losing genetic material in the process. Epilepsy is a significant attribute of r(14), and many believe the ring structure of the chromosome plays a role in the development of seizures. The gene material that is lost is thought to cause the inactivity of other gene materials present in the ring, thereby upsetting the functions of the brain; genes in ring chromosome 14 don’t function at the same level as genes in the standard chromosome 14. Because of this, individuals with r(14) experience certain symptoms, such as epilepsy, and would largely benefit from medical, as well as familial, support.
References
Chromosome 14 ring – symptoms, causes, treatment: Nord. National Organization for Rare Disorders. (2009, April 10). https://rarediseases.org/rare-diseases/chromosome-14-ring/
Ring 14. (n.d.). Unique Understanding Genes & Chromosomes. https://www.rarechromo.org/media/information/Chromosome%2014/Ring%2014%20FTNP.pdf
Ring 14 Syndrome. (n.d.). Children’s Hospital Colorado. https://www.childrenscolorado.org/conditions-and-advice/conditions-and-symptoms/conditions/ring14/
Said, R. R. (2021). Ring Chromosome 14 Syndrome. Child Neurology Foundation. https://www.childneurologyfoundation.org/disorder/ring-chromosome-14-syndrome/
