Imprinting disorders in humans: a review

Area of Science:

• Genetics
• Epigenetics
• Developmental Biology

Background:

• Mammals possess two sets of chromosomes, typically exhibiting equal autosomal gene expression from both parents.
• A small fraction of human genes (<1%) are imprinted, meaning they are expressed from only one parent without structural alteration, often via DNA methylation.
• Imprinted genes play a significant role in fetal growth and development.

Purpose of the Study:

• To review human disorders associated with imprinted gene errors.
• To highlight the impact of environmental and nutritional factors on DNA methylation and imprinted gene function.
• To underscore the importance of understanding epigenetic processes for improved patient care.

Main Methods:

• Review of scientific literature on genomic imprinting and associated human disorders.
• Analysis of epigenetic mechanisms, including DNA methylation, in regulating imprinted gene expression.
• Examination of environmental and nutritional influences on fetal development and imprinting.

Main Results:

• Imprinting errors are linked to numerous human disorders, including Prader-Willi syndrome, Angelman syndrome, Silver-Russell syndrome, and Beckwith-Weidemann syndrome.
• Specific chromosomal regions and genes (e.g., chromosome 15q11.2-q13.3, GNAS gene) are implicated in various imprinting disorders.
• Environmental factors and nutrition during periconceptional and intrauterine periods can affect DNA methylation, influencing fetal development and potentially causing pregnancy complications.

Conclusions:

• Epigenetic regulation of imprinted genes is critical for normal development.
• Disruptions in imprinting can lead to significant congenital disorders and developmental abnormalities.
• Further understanding of imprinting mechanisms and their environmental modulation is essential for advancing clinical diagnosis and treatment strategies.