F13A1 and hyperinsulinemic hypoglycemia, familial, 4: rWGS identified homozygous variants in F13A1 (OMIM#613225; Factor XIIIA deficiency), and he was immediately started on prophylaxis with recombinant coagulation FXIII A-subunit, decreasing his risk for another central nervous system (CNS) bleed and the associated potential neurologic complications and mortality.