A 71-kilodalton protein is a major product of the Duchenne muscular dystrophy gene in brain and other nonmuscle tissues.

The known Duchenne muscular dystrophy (DMD) gene products, the muscle- and brain-type dystrophin isoforms, are 427-kDa proteins translated from 14-kilobase (kb) mRNAs.
Recently we described a 6. 5-kb mRNA that also is transcribed from the DMD gene.
Cloning and in vitro transcription and translation of the entire coding region show that the 6. 5-kb mRNA encodes a 70. 8-kDa protein that is a major product of the DMD gene.
It contains the C-terminal and the cysteine-rich domains of dystrophin, seven additional amino acids at the N terminus, and some modifications formed by alternative splicing in the C-terminal domain.
It lacks the entire large domain of spectrin-like repeats and the actin-binding N-terminal domain of dystrophin.
This protein is the major DMD gene product in brain and other nonmuscle tissues but is undetectable in skeletal muscle extracts.

