Congenital stromal corneal dystrophy
Encyclopedia
Congenital stromal corneal dystrophy (CSCD), also called Witschel dystrophy, is an extremely rare, autosomal
dominant form of human corneal dystrophy
. It is non-progressive and is linked to mutations in DCN gene encoding decorin
protein. Only 4 families have been reported to have the disease by 2009. The main features of the disease are numerous opaque flaky or feathery areas of clouding in the stroma that multiply with age and eventually preclude visibility of the endothelium. Strabismus or primary open angle glaucoma was noted in some of the patients. Thickness of the cornea stays the same, Descemet's membrane and endothelium are relatively unaffected, but the fibrills of collagen that constitute stromal lamellae are reduced in diameter and lamellae themselves are packed significantly more tightly.
CSCD is associated with a mutation in the gene that encodes the protein decorin
, located at chromosome
12q22. The disorder is inherited in an autosomal dominant manner, which indicates that the defective gene responsible for a disorder is located on an autosome
(chromosome 12 is an autosome), and only one copy of the gene is sufficient to cause the disorder, when inherited from a parent who has the disorder.
Autosome
An autosome is a chromosome that is not a sex chromosome, or allosome; that is to say, there is an equal number of copies of the chromosome in males and females. For example, in humans, there are 22 pairs of autosomes. In addition to autosomes, there are sex chromosomes, to be specific: X and Y...
dominant form of human corneal dystrophy
Corneal dystrophy (human)
Human corneal dystrophy is a group of disorders, characterised by a noninflammatory, inherited, bilateral opacity of the transparent front part of the human eye called the cornea...
. It is non-progressive and is linked to mutations in DCN gene encoding decorin
Decorin
Decorin is a proteoglycan on average 90 - 140 kilodaltons in size.It belongs to the small leucine-rich proteoglycan family and consists of a protein core containing leucine repeats with a glycosaminoglycan chain consisting of either chondroitin sulfate or dermatan sulfate .Decorin is a small...
protein. Only 4 families have been reported to have the disease by 2009. The main features of the disease are numerous opaque flaky or feathery areas of clouding in the stroma that multiply with age and eventually preclude visibility of the endothelium. Strabismus or primary open angle glaucoma was noted in some of the patients. Thickness of the cornea stays the same, Descemet's membrane and endothelium are relatively unaffected, but the fibrills of collagen that constitute stromal lamellae are reduced in diameter and lamellae themselves are packed significantly more tightly.
Genetics
Decorin
Decorin is a proteoglycan on average 90 - 140 kilodaltons in size.It belongs to the small leucine-rich proteoglycan family and consists of a protein core containing leucine repeats with a glycosaminoglycan chain consisting of either chondroitin sulfate or dermatan sulfate .Decorin is a small...
, located at chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
12q22. The disorder is inherited in an autosomal dominant manner, which indicates that the defective gene responsible for a disorder is located on an autosome
Autosome
An autosome is a chromosome that is not a sex chromosome, or allosome; that is to say, there is an equal number of copies of the chromosome in males and females. For example, in humans, there are 22 pairs of autosomes. In addition to autosomes, there are sex chromosomes, to be specific: X and Y...
(chromosome 12 is an autosome), and only one copy of the gene is sufficient to cause the disorder, when inherited from a parent who has the disorder.