We examined the region just distal to PTCHD1 in detail and identified a number of putative enhancer and promoter sequences, as well as conserved (and putative regulatory) elements (Fig. 1). We also identified several overlapping spliced long (>200nt) non-coding (nc) RNAs (PTCHD1AS1 (from cDNA clone IMAGE:1560626; BX115199) and PTCHD1AS2 (from cDNA clone BRSTN2000219; DA355362)), which map to the opposite strand and distal to PTCHD1 (see Fig. 1). 5’RACE (Rapid Amplification of cDNA Ends) shows that a number of splice variants of these transcripts originate at the CpG island just upstream of PTCHD1, encompassing its putative promoter. Similar antisense transcripts are present at syntenic loci in other mammalian species, at least two exons of which appear to be conserved between rat, mouse and humans (Fig. 1).
