Generation and characterization of induced pluripotent stem cell (iPSC) lines from two symptomatic carriers of pathogenic TNNI3 variants and two non-carrier relatives

Pediatric restrictive cardiomyopathy (RCM) is a rare, life-threatening heart disorder characterized by myocardial stiffness and impaired ventricular relaxation. It is often linked to pathogenic TNNI3 variants, which affect cardiac troponin I, a key regulator of myocardial contraction and relaxation. We generated induced pluripotent stem cell (iPSC) lines from two affected children, carrying the c.574C > T(p.Arg192Cys) and c.509G > A (p.Arg170Gln) variants, and from two unaffected family members. All iPSC lines exhibited typical morphology, expressed markers of undifferentiated state, and demonstrated multipotent differentiation potential. These patient-specific lines provide a physiologically relevant platform to investigate disease mechanisms and develop targeted therapies for TNNI3-associated RCM.