XRCC4 and hyperinsulinemic hypoglycemia, familial, 4: Indeed, tumors and cytopenia observed in some XRCC4 patients also remind cancer susceptibility in LIG4 deficiency [31], Fanconi anemia [MIM:PS227650], Ataxia-Teleangiectasia [MIM#208900], and more broadly, genomic instability syndromes such as Mosaic Variegated Aneuploidy [PS257300].