Uniparental disomy

If there is a uniparental disomy (UPD ), originate both chromosomes of a homologous pair of chromosomes from one parent.

If it is to both chromosomes of a parent, this is called heterodisomy that same chromosome is present twice, this as isodisomy ( alleles identical) is called. In the context of genetic imprinting ( embossing), a disomy cause overexpression or loss of genetic expression. ( see, eg, Angelman syndrome, Prader -Willi syndrome). In such a case, can not complement each other, the maternal ( maternal ) and paternal ( fatherly ) features.

The most common cause for the development of a UPD disomy is suspected in the oocyte, resulting in a trisomic zygote. By correcting the trisomy can occur to a disomic embryo with maternal uniparental disomy (eg disomy of chromosome 15, Prader -Willi syndrome).