Aneuploidy – trisomy of the 21 chromosome

Abstract

Trisomija kromosoma 21 je vrsta aneuploidije, tj. genetički poremećaj koji uzrokuje bolest pod nazivom Down-ov sindrom (DS). Karakteristična obilježja te bolesti su mentalna zaostalost, zastoj u fizičkom rastu i razvoju, te karakterističan izgled glave djeteta. Očekivani životni vijek djece je u prosjeku smanjen za polovicu. Na učestalost pojave Down-ova sindroma kod djece utjecaj ima životna dob majki pri začeću, pa je pojavnost ovoga sindroma češća kod starijih trudnica. Bolest se može otkriti već u prenatalnoj fazi pomoću različitih postupaka, kao što su npr. biopsija i amniocenteza, a u posljednje su se vrijeme javili i neki novi, manje riskantni, postupci. Postoje i različiti testovi za prenatalnu detekciju bolesti koji nisu preterano pouzdani. Bolest i njeni uzroci i posljedice se uvelike istražuju, no još uvijek se o njoj premalo zna, te se otkrivanje lijeka ili pogodne terapije za liječenje ne očekuje u narednih desetak godina, pa i više. Pojava mišjih modela sa DS je stvorila nove mogućnosti za daljnja istraživanja i razumijevanje uzroka genskih poremećaja.Chromosome trisomy 21 is a type of aneuploidy (a genetic disorder) which causes Down syndrome (DS). This disease has specific symptoms such as mental retardation, slower mental and physical development and distinctive facial and head features. The life expectancy of mongoloid children is in average one half shorter than at normal life expectancy. The age of the mother at conception has an effect on the frequency of Down syndrome, therefore, an older mother is more likely than a younger mother to have a baby with the syndrome. The disease can be detected at the prenatal stage with the help of different procedures such as biopsy and amniocentesis. Some new and less risky procedures were recently developed. There are also several tests for prenatal detection of the disease which are not so reliable. The disease and its causes are being studied but the number of information is still too small to expect finding the cure or an appropriate method of treatment in the next ten years or even longer. New possibilities for further research and understanding of the disorder have been created with the emersion of mouse models with DS