Techniques such as RT-PCR, multiplex genomic PCR, and sequence analysis (cDNA and genomic DNA), used for the diagnosis of genetic diseases, are performed on a research basis. If RT-PCR tests result in cDNA showing the absence of an entire exon or exons, then multiplex genomic PCR testing is performed. Multiplex genomic PCR testing amplifies the nine exons of the HPRT1 gene as eight PCR products. If the exon in question is deleted, the corresponding band will be missing from the multiplex PCR. However, if the exon is present, the exon is sequenced to identify the mutation, therefore causing exclusion of the exon from cDNA. If no cDNA is created by RT-PCR, then multiplex PCR is performed on the notion that most or all of the gene is obliterated. Treatment
Treatment for LNS is symptomatic. Gout can be treated with allopurinol to control excessive amounts of uric acid. Kidney stones may be treated with lithotripsy, a technique for breaking up kidney stones using shock waves or laser beams. There is no standard treatment for the neurological symptoms of LNS. Some may be relieved with the drugs carbidopa/levodopa, diazepam, phenobarbital, or haloperidol.It is essential that the overproduction of uric acid be controlled in order to reduce the risk of nephropathy, nephrolithiasis, and gouty arthritis. The drug allopurinol is utilized to stop the conversion of oxypurines into uric acid, and prevent the development of subsequent arthritic tophi (produced after having chronic gout), kidney stones, and nephropathy, the resulting kidney disease.
On the other hand, the consumption of oily fish, in a diet similar to that which doctors recommend for age related macular degeneration, can be used to slow the progression of the disease.Advances in technology have brought devices that help Stargardt patients who are losing their vision maintain their independence. Low-vision aids can range from hand lenses to electronic devices and can allow those losing their vision to be able to carry out daily activities. Some patients may even opt for in-person services. Prognosis
The long-term prognosis for patients with Stargardt disease is widely variable and depends on the age of onset and genetic alleles.The majority of patients will progress to legal blindness, which means that central reading vision will be lost. However, perimetry and microperimetry studies indicate that the peripheral light sensitivity is preserved over a long time in a significant fraction of all patients (i.e., >50%). Stargardt disease has no impact on general health and life expectancy is normal. Some patients, usually those with the late-onset form, can maintain excellent visual acuities for extended periods and are therefore able to perform tasks such as reading or driving. Epidemiology
A 2017 prospective epidemiologic study that recruited 81 patients with STGD over 12 months reported an incidence of between 1 and 1.28 per 10 000 individuals. The median age of presentation was 27 years (range 5–64 years), most (90%) were symptomatic, with a median visual acuity of Snellen equivalent 20/66. History
Karl Stargardt (1875–1927) was a German ophthalmologist born in Berlin.