Second-generation sequencing across the
locus revealed an ~11 kb heterozygous deletion. Affected individual IV-4 of kindred 0124 (red bar) was subjected to second-generation sequencing across the APC locus including the promoter, exons and introns. A heterozygous deletion approximately 44 kb upstream of APC exon 1A was found between coordinates chr5:112,034,824 and chr5:112,045,845 (GRCh37/hg19) which encompasses exon and promoter 1B (Genbank D13981.1). Other studies (Snow et al., Rohlin et al., and Kadiyska et al.) have reported larger promoter deletions in this region [6,8-10] (blue bars).