Immunodeficiency, Centromeric Instability, Facial Anomalies (ICF) Syndrome, Due to ZBTB24 Mutations, Presenting with Large Cerebral Cyst

The immunodeficiency, centromeric instability, facial anomalies (ICF) syndrome is an autosomal recessive disease presenting with immunodeficiency secondary to hypo- or agamma-globulinemia, developmental delay, and facial anomalies. Centromeric instability is the cytogenetic hallmark of the disorder which results from targeted chromosomal rearrangements related to a genomic methylation defect. We describe a patient carrying a homozygous mutation of the ZBTB24 gene, which has been recently shown to be responsible for ICF syndrome type 2. Our patient presented with intellectual disability, multiple café-au-lait spots, and a large cerebral arachnoidal cyst. Although laboratory signs of impaired immune function, such as reduced serum IgM were detected, our patient did not present clinical manifestations of immunodeficiency. Brain malformations abnormalities have not been reported so far in ICF syndrome and it can be speculated that ZBTB24 mutations may alter cerebral development. Nevertheless, we cannot rule out that the presence of the cerebral cyst in the patient is coincidental. In summary, our patient illustrates that clinical evidence of immunodeficiency is not a universal feature of ICF2 syndrome type 2 and suggests that brain malformations may be present in other ICF cases.