GENDIA

Diagnostic tests for genetic diseases can be divided into cytogenetics, molecular cytogenetics (FISH) and molecular genetics. Whereas cytogenetic and molecular cytogenetic tests are widely available, molecular tests for many genetic diseases are not available in many countries. Several decades of intensive research on the molecular causes of human genetic diseases have resulted in a large list of molecular tests that can be offered to diagnose genetic diseases. In many countries molecular laboratories have been established that offer these tests to patients and their families. Unfortunately, there are huge differences with respect to accessibility, price and quality of the molecular diagnostic testing in the various countries. The spectrum of genetic diseases that can be tested varies from several hundreds in countries with a well-developed service system to only a few in most countries of the world. One of the main problems is the relative rareness of most genetic diseases, resulting in a small number of requests per disease per laboratory. This impairs a cost-effective and reliable service. A second problem is the large number of genetic diseases that can be tested for by DNA technology (now over 2000). Since most laboratories offer less than 50 molecular tests, usually for the same diseases, the majority of genetic disorders cannot be diagnosed locally or even nationally. For these rare diseases it can be quite difficult to find a laboratory willing to do the test. Even when a laboratory is found, the turn around time and financial requirements usually are uncertain. Furthermore, it is difficult to check whether minimal quality requirements are met as quality trials are not offered for this category of diseases and there are no platforms where referring clinicians can discuss their positive and negative experiences.