This XPA polymorphism and nine new polymorphic markers that map in the MSSE region were typed in eleven MSSE families; XPA was excluded as the MSSE gene and the most likely location of MSSE was reduced to the interval between D9S197 and (D9S287, D9S1809).
This transcript map encompasses both the HSN-I critical interval and the locus for multiple self-healing squamous epithelioma (MSSE, previously named ESS1).
This distinguishes MSSE from the Marfan syndrome-related disorders in which missense mutations in TGFBR1 lead to developmental defects with vascular involvement but no reported predisposition to cancer.
The intronic variant was predicted to mediate in-frame exon 5 skipping within the serine/threonine kinase (STK) domain, which may also be mediated by a similar TGFBR1 variant of a splice acceptor site in intron 4 (c.806-2 A > C), identified in a British familial case of MSSE.