We created induced pluripotent stem cell (iPSC) lines from 1 patient with total colonic aganglionosis (with the G731del mutation in RET) and from 2 patients with S-HSCR (without a RET mutation), as well as RET<sup>+/-</sup> and RET<sup>-/-</sup> iPSCs.
While RET common variants are strongly associated with the commonest manifestation of the disease (males; short-segment aganglionosis; sporadic), rare coding sequence (CDS) variants are more frequently found in the lesser common and more severe forms of the disease (females; long/total colonic aganglionosis; familial).Here we present the screening for RVs in the RET CDS and intron/exon boundaries of 601 Chinese HSCR patients, the largest number of patients ever reported.
The findings suggest that both RET and NTRK3 mutations acting together are necessary and sufficient for the appearance of the disease, and that the EDN3 mutation is acting as a phenotype-modifier factor in the context of this family, as two different HSCR phenotypes are seen among the affected members: a short segment form, and a total colonic aganglionosis.
Potential disease-related RET gene mutations include exon 17-21 genetic variations that suggest the possibility of disrupted downstream signaling pathways from vital gene recruitment sites as possible TCA contributing factors.
In the interests of simplifying genetic molecular diagnosis, I suggest the following guidelines: 1) only in cases of total colonic aganglionosis (TCA) is it advisable to carry out full RET mutation screening (the mutation rate is up to 70 %); and 2) all HSCR patients should be tested only for standard MEN2A and MTC mutations.
Relationship between the type of RET/GDNF/NTN or SOX10 gene mutations and long-term results after surgery for total colonic aganglionosis with small bowel involvement.