has material basis in germline mutation in predisposes towards IGKC inborn error of immunity hereditary disease infectious disease recurrent infections associated with rare immunoglobulin isotypes deficiency https://github.com/monarch-initiative/mondo/issues/4521 https://github.com/monarch-initiative/mondo/issues/6747 https://github.com/monarch-initiative/mondo/issues/6877 https://github.com/monarch-initiative/mondo/issues/9453 https://www.malacards.org/card/immunoglobulin_kappa_light_chain_deficiency https://www.malacards.org/card/recurrent_infections_associated_with_rare_immunoglobulin_isotypes_deficiency IgG subclass deficiency with IgA subclass deficiency MONDO:0013576 NANDO:2200719 recurrent infections associated with rare immunoglobulin isotypes deficiency Deficiencies in immunoglobulin (Ig) isotypes (including: isolated IgG subclass deficiency, IgG subclass deficiency with IgA deficiency and kappa chain deficiency) are primary immunodeficiencies that are often asymptomatic but can be characterized by recurrent, often pyogenic, sinopulmonary infections. IMMUNOGLOBULIN kappa LIGHT chain deficiency UMLS:C3279824 MESH:C564131 Some patients may show an increased frequency of infections in their second year of life, while for others the onset of infections may be later. There are four subclasses of IgG (IgG1, IgG2, IgG3 and IgG4), the levels of which change with age. Deficiency with IgG subclass 2 is most common in children, whereas after puberty deficiency in subclass 3 is more common. Symptomatic patients experience recurrent sinopulmonary infections, particularly with Streptococcus pneumonia and Haemophilus influenza, which present as repeated ear infections, bronchitis, pneumonia, sinusitis and diarrhea. Patients may also present with meningitis, bronchiectasis and severe, recurrent otitis media, which may lead to hearing loss. Patients with kappa chain deficiency are usually asymptomatic but symptoms can include recurrent respiratory infections and diarrhea. Orphanet:183675 isolated IgG subclass deficiency kappa-chain deficiency GARD:0017086 MEDGEN:481454 OMIM:614102 IGKCD