Recurrent pyogenic infections [6 genes]

Defects in genes encoding components of the complement lectin pathway predispose carriers to recurrent infections. Deficiency of mannose-binding lectin (MBL) generally increases the risk of any infection type, although is mainly associated with higher frequency of pyogenic infections, including pneumococcal and sepsis, particularly in neonates/infants or in patients undergoing immunosuppressive treatments. Furthermore, primary C3 deficiencies due to defects in C3 cleavage products result in severe recurrent pyogenic infections due to ineffective opsonization of pathogens.

This diagnostic panel is highly specific when there is a biochemical deficiency in components of the complement lectin pathway as an inherent cause of predisposition to infections. Therefore, in the absence of a suspected deficiency of complement factors of this pathway, the panel of primary immunodeficiencies should be recommended.

• Recurrent infections
• Severe pyogenic infections
• Onset: childhood, adulthood

• Unknown
• Few families described

• Diagnosis and genetic counseling
• Purified MBL (under development)
• Vaccination
• Prophylactic antibiotics

The identification of a pathogenic variant in the genes of the panel allows for a precise molecular diagnosis, in addition to providing genetic advice. Positive genetic testing can help direct patient management and evaluate treatment options.