Blood Coagulation/genetics; Factor VIII/genetics; Hemophilia A/genetics; Introns; Mutation; Adult; Base Sequence; Blood Coagulation/drug effects; Case-Control Studies; DNA Mutational Analysis; Deamino Arginine Vasopressin/therapeutic use; Factor VIII/metabolism; Female; Genetic Predisposition to Disease; HEK293 Cells; Hemophilia A/blood; Hemophilia A/diagnosis; Hemophilia A/drug therapy; Hemostatics/therapeutic use; Heredity; Humans; Italy; Male; Middle Aged; Molecular Sequence Data; Pedigree; Phenotype; RNA Splice Sites; RNA, Messenger/analysis; Sequence Analysis, RNA; Severity of Illness Index; Transfection; Young Adult