X chromosome lookup in igv.js - fix #283
X chromosome lookup in igv.js - fix #283

macarthur-lab/seqr,macarthur-lab/xbrowse,ssadedin/seqr,macarthur-lab/seqr,macarthur-lab/seqr,ssadedin/seqr,macarthur-lab/xbrowse,macarthur-lab/xbrowse,ssadedin/seqr,macarthur-lab/seqr,ssadedin/seqr,macarthur-lab/seqr,macarthur-lab/xbrowse,ssadedin/seqr,macarthur-lab/xbrowse,macarthur-lab/xbrowse