SNP Shot: Genomic Insights

Enlarged parietal foramina (EPF) is a genetic disorder affecting skull development. It results in abnormally large holes (foramina) in the parietal bones, the two bones making up the upper and side regions of the skull. This occurs because the parietal bones don't fully solidify or ossify. These symmetrical, circular openings vary in size, from millimeters to centimeters. Parietal foramina are normally present during fetal development and typically close by the fifth month of pregnancy. In individuals with EPF, these foramina persist throughout their lives.

The enlarged foramina are soft because the bone is missing. Most individuals with EPF experience no related health issues. However, in a small percentage, scalp defects, seizures, and brain structure abnormalities have been observed. Applying pressure to these openings can cause intense headaches. Individuals with EPF also face a heightened risk of brain injury or skull fracture if they experience trauma near the openings.

There are two types of EPF, type 1 and type 2, distinguished by their different genetic origins.

Inheritance:

EPF is inherited in an autosomal dominant manner. This means that inheriting just one copy of the mutated gene in each cell is enough to cause the condition. In most instances, an affected individual has a parent who also has the condition. However, in rare instances, individuals who inherit the altered gene may not exhibit enlarged parietal foramina, a phenomenon called reduced penetrance.