We have determined the chromosomal location of the human cardiac/slow skeletal muscle troponin C gene (TNNC1) to the short arm of chromosome 3 using somatic cell hybrids. PCR-based analysis of a 'monochromosomal' hybrid panel identified the presence of the TNNC1 gene on human chromosome 3 and subsequent analysis of the Genebridge4 radiation hybrid panel located the gene between D3S3118 (7.3cR) and GCT4B10 (4.2cR) with a lod score of > 3.0.