Biallelic PV/LPVs of NBN are the cause of Nijmegen breakage syndrome (NBS), an autosomal recessive disease characterized by chromosomal instability that determines progressive microcephaly, intrauterine growth retardation and short stature, recurrent sinopulmonary infections, an increased risk for cancer, and premature ovarian failure in females [32]. This evidence concerns the gene NBN and Nijmegen breakage syndrome.