Familial disseminated superficial actinic porokeratosis

Gene: FDPS

Comment on list classification: Updated rating from Red to Green after clinical discussion with Helen Brittain. Reasonable to include cases where DSAP and DSP have not been distinguished because it is sometimes hard to completely differentiate disseminated superficial actinic porokeratosis (DSAP) from disseminated superficial porokeratosis (DSP) in a clinical setting. Sufficient DSAP/DSP cases in PMID:26202976/27422687 to support causation.

Created: 7 Sep 2017, 10:40 a.m.

Comment on mode of inheritance: Monoallelic MOI supported by Zhang et al. (2015, PMID:26202976).

Created: 7 Sep 2017, 10:37 a.m.

Added 'deletions' tag based on large deletions found in 2 patients in PMID:26202976, including a 3,304-bp deletion.

Created: 7 Sep 2017, 10:36 a.m.

Zhang et al. (2015, PMID:26202976) screened 12 isoprenoid genes in 134 Chinese probands with porokeratosis. A total of 4 (don't specify relatedness) patients had FDPS mutations (2 familial, 2 sporadic). Note that DSAP and DSP subtypes (actinic and nonactinic) of porokeratosis are grouped together in this paper. Supplementary File 2 lists 4 variants (2 large deletions, a missense, and a splicing defect) 3 of which are included in OMIM.

Created: 7 Sep 2017, 10:31 a.m.

PMID:27422687 (Li et al., 2016) examined 10 families and 12 sporadic cases with different subtypes of porokeratosis in the Chinese population. One novel splice mutation c.773 + 1 G>A of FDPS was identified in the proband of family 10 with DSAP/DSP.

Created: 22 Jun 2017, 7:49 a.m.

Red List (low evidence)