The genes identified in these two syndromes are the nicotinic acetylcholine receptor alpha-4 subunit and potassium voltage-gated channel subfamily KQT member 2 respectively. Mutations in these genes lead to the clinical manifestations found in these disorders. It is theorized that deletions in these regions from the ringed chromosome may lead to epilepsy in affected patient. A similar association between a ring chromosome and an autosomal-dominant disease has been reported for ring 17 chromosome and Miller-Dieker syndrome. The recurrence risk for ring chromosome 20 syndrome is very low. The ring formation is typically not identified in parents, and occurs de novo during pre-natal development. Diagnosis
The ring 20 abnormality may be limited to as few as 5% of cells, so a screen for chromosomal mosaicism is critical. Newer array technology will not detect the ring chromosome and the standard metaphase chromosome analysis has been recommended. A karyotype analysis examining at least 50 cells should be requested to properly detect mosaicism. Treatment
Successful management of seizures plays a key role in improving quality of life. Antiepileptic medications are the main therapies for seizures; however, it appears that seizures in this syndrome do not respond well to drugs. In the cases reported in literature, numerous new and old antiepileptic drugs have been tried, but no one drug appears to be more efficacious than others. Therefore, no recommendations can be made regarding the selection of the most appropriate antiepileptic drug.
Diagnosis
Grovers may be suspected by its appearance, but since it has such a characteristic appearance under the microscope a shave skin or punch biopsy is often performed. Treatment
Sweating causes lesions to form, but lesions aggravated by sweat usually return to "normal" fairly quickly—avoiding sweat is not considered a reason to avoid exercise. Minor outbreaks can be controlled with prescription strength topical cortisone creams. More severe eruptions usually clear up after treatment for one to three months with Accutane or tetracycline. If these fail or the outbreak is severe, PUVA phototherapy treatments, antifungal medication and cortisone injections are alternatives.Some research has suggested a correlation of Grovers disease with mercury toxicity in which case Dimercaptosuccinic acid might help. Epidemiology
The prevalence and incidence of Grovers disease have not been firmly established. In a study from Switzerland, Grovers disease was diagnosed in just 24 of more than 30,000 skin biopsies. Grovers disease is mainly seen in males over the age of forty.Grovers disease affects chiefly white adults in the fifth decade or later, and appears to be around 1.6 to 2.1 times more common in men than in women. Grovers disease appears less commonly in darker-skinned individuals. History
This condition was first reported in 1975 by the American dermatopathologist, Ralph Wier Grover (1920–2008) while working at Franklin Hospital in New York. He described and examined around 40 patients having the characteristic signs of the disease, which now bears his name. References
External links
 Media related to Transient acantholytic dermatosis at Wikimedia Commons