What is the role of genomic imprinting in uniparental disomy disorders?

Genomic imprinting is a phenomenon where certain genes are expressed in a parent-of-origin-specific manner, leading to the exclusive expression of either the maternal or paternal allele. In the context of uniparental disomy (UPD), where both copies of a chromosome are inherited from one parent, genomic imprinting plays a critical role in gene expression.

In cases of UPD where a child inherits two copies of a chromosome from one parent (either both maternal or both paternal), the lack of expression from the genes imprinted by the other parent can lead to aberrant gene expression. For instance, if both copies are from the mother, the paternal alleles that are normally expressed in a healthy individual may be absent. This imbalance can disrupt the normal physiological processes that rely on the correct dosage and functional presence of both maternal and paternal alleles, resulting in various developmental disorders or syndromes.

Thus, the correct answer highlights the significance of genomic imprinting in the context of uniparental disomy disorders by indicating that the resulting gene expression patterns can be abnormal, leading to potential health issues associated with the specific genes involved.