Molecular Testing For Imprinting Disorders

Imprinting disorders are a group of rare diseases with a broad phenotypic spectrum caused by a wide variety of genetic and epigenetic disturbances of imprinted genes or gene clusters. The molecular genetic causes and their respective frequencies vary between the different imprinting disorders so that each has its unique requirements for the diagnostic workflow, making it challenging. To add even more complexity to this field, new molecular genetic causes have been identified over time and new technologies have enhanced the detectability e. g. of mosaic disturbances.The precise identification of the underlying molecular genetic cause is of utmost importance in regard to recurrence risk in the families, tumour risk, clinical management and conventional and in the future therapeutic managements.Here we give an overview of the imprinting disorders, their specific requirements for the diagnostic workup and the most common techniques used and point out possible pitfalls.