Pressure Overload in Mice With Haploinsufficiency of Striated Preferentially Expressed Gene Leads to Decompensated Heart Failure.

Striated preferentially expressed gene (Speg) is a member of the myosin light chain kinase family of proteins. Constitutive Speg deficient (Speg) mice develop a dilated cardiomyopathy, and the majority of these mice die or shortly after birth. In the present study we assessed the importance of Speg in adult mice.

SPEG-deficient skeletal muscles exhibit abnormal triad and defective calcium handling.

Centronuclear myopathies (CNM) are a subtype of congenital myopathies (CM) characterized by skeletal muscle weakness and an increase in the number of central myonuclei. We have previously identified three CNM probands, two with associated dilated cardiomyopathy, carrying striated preferentially expressed gene (SPEG) mutations. Currently, the role of SPEG in skeletal muscle function is unclear as constitutive SPEG-deficient mice developed severe dilated cardiomyopathy and died in utero.