Transcriptome analysis suggests Ca2+ handling is altered in SMA heart. a Shown is a “volcano plot” of statistical significance versus transcript fold change in SMA compared to unaffected control hearts. A total of 1178 transcripts were up- or down-regulated in SMA heart. b Heat map illustrating a subset of genes that were significantly changed. Red denotes high expression, blue denotes low expression. Of note, the principal gene regulating Ca2+uptake into the sarcoplasmic reticulum, Atp2a2 (SERCA2), was downregulated.