It is characterized by variable reductions in serum immunoglobulin (IgG, IgM and/or IgA) levels which cause most ICF patients to succumb to infectious diseases before adulthood.

ICF syndrome patients exhibit facial anomalies which include hypertelorism, low-set ears, epicanthal folds and macroglossia.

[6][7] The HELLS gene is located on chromosome 10 (10q23.33)[citation needed] The ZBTB24 gene is located on chromosome 6 (6q21)[citation needed] This disease is inherited in an autosomal recessive manner.

In 2007, Gennery et al. cured the humoral and cellular immunological defect in three ICF1 patients by hematopoietic stem cell transplantation (HSCT).

[8] This is the only documented case of restoring the immune conditions and growth improvement in these patients.