SNP Shot: Genomic Insights

Intestinal pseudo-obstruction is a condition where the digestive tract's ability to move food through is impaired due to issues with muscle contractions. This can happen at any age and can present with symptoms from mild to severe. The cause can be either a problem with the intestinal muscles themselves (myogenic) or a problem with the nerves that control these muscles (neurogenic).

This condition results in a buildup of partially digested food within the intestines. This accumulation can lead to abdominal distention and pain, along with nausea, vomiting, and either constipation or diarrhea. Individuals affected often experience appetite loss and difficulty absorbing nutrients, potentially leading to malnutrition. While these symptoms mimic those of a physical intestinal blockage (obstruction), no such blockage is actually present in intestinal pseudo-obstruction.

Depending on the underlying cause of intestinal pseudo-obstruction, individuals may exhibit other signs and symptoms. Some experience bladder problems like difficulty urinating. Additional features may include reduced muscle tone (hypotonia) or stiffness (spasticity) in the torso and limbs, weakness in the muscles controlling eye movement (ophthalmoplegia), intellectual disability, seizures, unusual facial characteristics, or frequent infections.

When intestinal pseudo-obstruction occurs without being linked to another health issue, it's termed primary or idiopathic intestinal pseudo-obstruction. However, the condition can also arise as a complication of another underlying medical problem, in which case it is considered secondary intestinal pseudo-obstruction. It can present as either an acute (episodic) or chronic (persistent) condition.

Inheritance:

Intestinal pseudo-obstruction is often not inherited, and most affected individuals have no family history of it. However, when it does run in families, it can follow various inheritance patterns.

Intestinal pseudo-obstruction resulting from mutations in the FLNA gene follows an X-linked recessive inheritance pattern. The FLNA gene resides on the X chromosome, one of the two sex chromosomes. In males, who have only one X chromosome, having a single altered copy of the gene in each cell is enough to cause the condition. In females, who possess two X chromosomes, both copies of the gene would need to be mutated for the disorder to manifest. Consequently, X-linked recessive disorders affect males much more frequently than females, as it's less probable for females to have two altered copies of the gene. A key characteristic of X-linked inheritance is that fathers cannot transmit X-linked traits to their sons.

Intestinal pseudo-obstruction resulting from mutations in the ACTG2 gene follows an autosomal dominant inheritance pattern. This means that having only one copy of the altered gene in each cell is sufficient to cause the condition.

Some other instances of intestinal pseudo-obstruction are inherited in an autosomal recessive pattern, which requires both copies of the gene in each cell to be mutated. In autosomal recessive conditions, each parent of an affected individual carries one copy of the mutated gene, but they usually do not display any signs or symptoms of the condition.