Zone of Polarizing Activity Regulatory Sequence Mutations/Duplications with Preaxial Polydactyly and Longitudinal Preaxial Ray Deficiency in the Phenotype: A Review of Human Cases, Animal Models, and Insights Regarding the Pathogenesis

Table 1

Human ZRS mutations/duplications in which there is PPD-LPAD association in the phenotype.

ZRS mutations/duplications	The phenotype
(A) Point mutations
ZRS 402 C>T	Werner syndrome phenotype
ZRS 404 G>A	Either Werner phenotype or PPD-five-fingered hand-tibial hemimelia phenotype
ZRS 404 G>T	Variable phenotypes of PPD-LPAD association
ZRS 404 G>C	Triphalangeal thumbs in the hands and PPD/tibial defects in the lower limbs
ZRS 406 A>G	Werner syndrome phenotype
ZRS 417 A>G	Mirror image polydactyly in all 4 limbs and bilateral tibial defects
ZRS 619 C>T	PPD-LPAD associations confined to the upper limbs. The lower limbs are normal
(B) Duplications
Microduplications (<80 kb) reported by Lohan et al. [15]	Laurin-Sandrow syndrome phenotype
96,605 bp duplication from nt 156,240,230 to nt 156,336,835 at 7q36.3	Syndactyly type IV with concurrent tibial hypoplasia

Werner syndrome: Tibial Hypoplasia, Polysyndactyly Triphalangeal Thumb Syndrome or THPTTS, OMIM 188770; Laurin-Sandrow syndrome: mirror-image polydactyly of the hands and feet, absent tibiae, and duplication of the fibulae; OMIM 135750; Syndactyly type IV: complete syndactyly of all digits with polydactyly, OMIM 186200.