SNP Shot: Genomic Insights

MyD88 deficiency is a genetic primary immunodeficiency, meaning it's an inherited immune system disorder that weakens the body's initial defense against pathogens (the innate immune response). This deficiency makes individuals highly susceptible to frequent and severe infections from specific bacteria called pyogenic bacteria, which cause pus formation. Interestingly, resistance to other common bacteria, viruses, fungi, and parasites remains normal. The most common culprits behind infections in MyD88 deficiency are Streptococcus pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa. Most individuals experience their first bacterial infection before the age of 2, and these infections can be life-threatening during infancy and childhood. The frequency of infections typically decreases around age 10.

Children with MyD88 deficiency are prone to invasive bacterial infections, affecting the bloodstream (septicemia), the membranes surrounding the brain and spinal cord (meningitis), or the joints (resulting in inflammation and arthritis). These invasive infections can also lead to abscesses, characterized by tissue breakdown and pus formation, on internal organs. Furthermore, individuals may experience localized infections in the ears, nose, or throat. Atypical for bacterial infections, a high fever may not be present initially, even in cases of severe infection.

Inheritance:

MyD88 deficiency follows an autosomal recessive inheritance pattern. This means that a person must inherit two copies of the mutated gene, one from each parent, to develop the condition. Parents who each carry only one copy of the mutated gene usually do not exhibit any symptoms of the disorder themselves.