Abstract
Spectacular progress has been made in the knowledge of human genetic material since the middle of the last century: the chromosomes have been characterised; the complete sequence of the genome has been identified. Also, all types of diseases hereditary and non-hereditary diseases (especially cancers) have been associated to changes in DNA structure and sequence. These developments have been accompanied by a great number of techniques, which have led to the investigation and characterisation of the human genetic load, and its application in clinical practice for the diagnosis of certain diseases. This has meant that, besides studies at molecular level for identifying a gene mutation, conventional cytology has extended to the detection of extremely small changes in the structure of the chromosome, giving rise to a new area of diagnosis called molecular cytogenetics. This includes various techniques that detect small changes, in decreasing order, from microdeletions and microduplications detectable by fluorescent probes (FISH), to genomic arrays and arrays based on compared genomic (CGH) which detect even smaller changes. However, due to their high resolution, arrays are capable of identifying variations in DNA, which in many cases its importance is still uncertain. This implies that even some of the most common techniques currently used, such as CGH, require a careful evaluation before offering a diagnosis.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call