imprintinghäiriöitä

Imprintinghäiriöitä, often translated as imprinting disorders, refers to a group of rare genetic conditions that disrupt the normal process of genomic imprinting. Genomic imprinting is a phenomenon where certain genes are expressed in a parent-of-origin-specific manner, meaning only the copy inherited from the mother or the father is active. This selective expression is regulated by epigenetic marks, such as DNA methylation, which are established during gamete formation and maintained throughout development.

Imprinting disorders arise when these epigenetic marks are incorrectly established or erased, leading to the inappropriate silencing or activation of imprinted genes. This disruption can occur through various mechanisms, including deletions, duplications, uniparental disomy (inheritance of both chromosome copies from one parent), or mutations in imprinting control regions. The consequences depend on which imprinted gene or genes are affected and the specific pattern of their malfunction.

Clinically, imprinting disorders manifest with a wide range of developmental and growth abnormalities. Some well-known examples include Prader-Willi syndrome and Angelman syndrome, which are caused by defects in the same chromosomal region (15q11.2-q13) but result in distinct phenotypes due to different parental origins of the genetic defect. Other imprinting disorders can lead to conditions like Beckwith-Wiedemann syndrome, Silver-Russell syndrome, and transient neonatal diabetes mellitus. Diagnosis typically involves genetic testing to identify the underlying molecular cause. Management is often supportive and focuses on addressing the specific symptoms and developmental challenges associated with the particular disorder.