Mutations in lymphoid-specific helicase (HELLS) and cell division cycle associated 7 (CDCA7) can cause a genetically heterogeneous autosomal recessive disorder referred to as centromeric instability and facial anomalies (ICF) syndrome, which is characterized by life-threatening immunodeficiency (Thijssen et al., 2015). The gene discussed is HELLS; the disease is ICF syndrome.