TNNI3 and craniodiaphyseal dysplasia: Recent studies have indicated that abnormal expression of cTnI contributes to the pathophysiology and development of CDD.9, 10, 11,24 Homozygous knock-in mice with cTnI R21C mutation developed hypertrophy after 12 months of age and exhibited abnormal diastolic function that is characterized by longer filling times and impaired relaxation.24