[Titin gene mutations in Chinese patients with dilated cardiomyopathy]

Titin is recently known as the largest protein which exists in the striated muscle sarcomere and is dynamic both in biomechanics properties and biochemical functions. Four possible disease-associated mutations located in three exons (3, 14, 49) of titin gene (TTN) have been identified in Japanese DCM patients in 2002. We observed the possible association of TTN mutation in Chinese patients with DCM.

Three exons of TTN (3, 14, 49) were screened in 117 DCM patients and 120 controls by polymerase chain reaction-single strand conformation polymorphisms (PCR-SSCP) and DNA sequence. SSCP was carried out following a protocol optimized for each PCR fragment after amplification. Abnormal SSCP results were subsequently confirmed by DNA sequencing.

The mutations reported in Japanese DCM patients were not identified in this patient cohort. A novel mutation [the G13053A (TTN cDNA sequence, X90568) change resulted in amino acid change at position 4351 (Gly4351Asp)] was found in two young DCM patients from a DCM family (1.7%). There was no similar mutation in controls.

This novel Gly4351Asp mutation in TTN might be associated with DCM.