Clinicopathologic correlation and genetic analysis in a case of posterior polymorphous corneal dystrophy.
OBJECTIVE
To evaluate the clinical history, histopathology, and genetics of posterior polymorphous corneal dystrophy (PPMD) in a woman with a prominent retrocorneal membrane.


METHODS
Observational case report and genetic analysis of her family, UM:139.


METHODS
Records were reviewed from a case and associated family members. The diagnosis of PPMD was based on clinical examination, immunohistochemical staining, electron microscopy, and screening of genetic markers from regions previously reported to be associated with PPMD.


RESULTS
Over 17 years, the proband with PPMD had 25 ocular procedures performed for glaucoma, cataract, cornea, retina, and postoperative problems. A prominent retrocorneal membrane grew onto the crystalline lens and intraocular lens (IOL). Histopathology revealed stratified epithelial-like cells on iris from an iridectomy and stratified corneal endothelium on a corneal button. Electron microscopy on the cornea revealed microvilli, tonofilaments, and desmosomes consistent with endothelial transformation, which was confirmed by positive anticytokeratin (CK) AE1/AE3 and CAM 5.2 immunoreactivity. Negative immunoreactivity in epithelium and positive in endothelium with anti-CK 7 supported the diagnosis of PPMD rather than epithelial downgrowth. Multiple relatives were affected with PPMD with apparent autosomal dominant inheritance, but surprisingly, the PPMD, congenital hereditary endothelial dystrophy 1 (CHED1) and CHED2 loci on chromosome 20 and the collagen, type VIII, alpha-2 (COL8A2) gene were excluded by linkage and haplotype analyses.


CONCLUSIONS
We are unaware of previous PPMD reports describing the unusual feature of a retrocorneal membrane extending onto the crystalline lens and IOL. In addition, this family suggests another PPMD locus.
Moroi
Sayoko E
SE
Department of Ophthalmology and Visual Sciences, W. K. Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan 48105, USA. smoroi@umich.edu
Gokhale
Parag A
PA
Schteingart
Miriam T
MT
Sugar
Alan
A
Downs
Catherine A
CA
Shimizu
Satoko
S
Krafchak
Charles
C
Fuse
Nobuo
N
Elner
Susan G
SG
Elner
Victor M
VM
Flint
Andrew
A
Epstein
Michael P
MP
Boehnke
Michael
M
Richards
Julia E
JE
D015415:Biomarkers / Q000032:analysis; D002874:Chromosome Mapping; D002890:Chromosomes, Human, Pair 20 / Q000235:genetics; D024102:Collagen Type VIII / Q000235:genetics; D003315:Cornea / Q000378:metabolism / Q000648:ultrastructure*; D003317:Corneal Dystrophies, Hereditary / Q000235:genetics* / Q000473:pathology*; D004247:DNA / Q000032:analysis; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D006801:Humans; D032801:Iridectomy; D007499:Iris Diseases / Q000473:pathology; D007633:Keratins / Q000378:metabolism; D007908:Lens, Crystalline; D007910:Lenses, Intraocular; D008566:Membranes; D018895:Microsatellite Repeats / Q000235:genetics; D008875:Middle Aged; D010375:Pedigree; D016133:Polymerase Chain Reaction
D015415:Biomarkers; C400901:CAM 5.2 antigen; C443712:COL8A2 protein, human; D024102:Collagen Type VIII; D007633:Keratins; D004247:DNA