Ch 12. Corneal Genetics

Question 1

Mutated gene associated to map-dot-fingerprint corneal dystrophy?

Answer 1

TGFB-I

Question 2

gene associated to recurrent epithelial erosion syndrome?

Answer 2

Not Known

Question 3

Gene associated to Meesman corneal dystrophy?

Answer 3

KRT3 y KRT12 on Cr12q13

Question 4

What type of inheritance has been described for Lisch corneal dystrophy?

Answer 4

X-Linked dominant

Question 5

name the TGFB-I corneal dystrophies

Answer 5

Reis-Bucklers Thiel-Behnke Lattice, and variants Granular corneal Dystrophy I & II

Question 6

Which are the common characteristics of TGFB-I corneal dystrophies?

Answer 6

bilateral, central, sparing 1-2mm of peripheral corneal, Autosomal Dominant.

Question 7

what is the role of TGFBI in corneal tissue

Answer 7

Although not clear, it possesses several protein binding domains, can bind to col 1,2 and 4 and is though to participate in celular adhesion.

Question 8

characterize macular corneal dystrophy

Answer 8

autosomal recessive, early childhood presentation, difuse stromal haze that goes al the way to the limbus. Primarily stromal, but advances posteriorly until it reaches Descemet and endothelium, and finally causes endothelial decompensation and produces severe corneal edema and visual loss in the 2-3rd decades.

Question 9

what substance accumulates in the macular corneal dystrophy?

Answer 9

Glicosaminoglicans in the stroma and endothelium, but not in the epithelium.

Question 10

which gene is responsible for MCD

Answer 10

multiple different mutations in the CHST6 encoding for sufotransferase 6.

Question 11

which gene is responsible for Schneider corneal dystrophy

Answer 11

UBIAD1 gene encoding for Ubi A phenyltransferase.

Question 12

gene responsible for congenital stromal corneal dystrophy

Answer 12

12q21.33 encoding for Decorin

Question 13

gene responsible for fleck corneal dystrophy

Answer 13

phosphatidylinositol-3-phosphate/phosphatidylinositol-5-kinase type III.

Question 14

is fleck corneal dystrophy progressive or not?

Answer 14

it is not progressive and asymptomatic

Question 15

which gene is responsible for central cloudy corneal dystrophy of Francois?

Answer 15

Although AD pattern has been described, no gene has been identified.

Question 16

name differences between early onset and classic forms of Fuchs endothelial dystrophy

Answer 16

classic: clinically evident around 5th decade, guttae are large, peaked, and located in cell edges. asociatted to SLC4a11 early:evident around 3rd to 4th decades. guttae are round, small, and located in cell center. associated to COL 8a2 gene

Question 17

Inheritance pattern of posterior polymorphous corneal dystrophy

Answer 17

autosomal dominant.

Question 18

general description of congenital endothelial corneal dystrophy

Answer 18

CHED (previously called CHED 2) in an autosomal recessive disease in the corneal endothelium, that is caracterized by bilateral, symmetric corneal haze that is present at birth. They present with nystagmus, and without epiphora or photophobia (opposite to PPCD, and in the group of PPCD previously classified as CHED1).

Question 19

clinical presentation of X-linked corneal dystrophy

Answer 19

congenital diffuse haze, with ground-glass appearance. There are indentations in the endothelium cause by focal absence of endothelial cells. Mapped to Xq25, but no gene identified.

Question 20

Is keratoconnus inheritable

Answer 20

Yes, twin studies have shown heritability, and an autosomal transition has been identified. No specific genes hace been demonstrated but there may be associations to protease regulation, wound healing associated proteins, or IL-1 mediated apoptosis . A locus at 13q32 has been implicated.

Question 21

Megalocornea`s inheritance

Answer 21

X-Linked although AD and AR have been reported.

Question 22

inheritance patterns of cornea plana

Answer 22

Both AR and AD have been reported. Mutations in keratocan gene- AR