An autosomal recessive condition (OMIM:217800) characterised by progressive minute, grey, punctate corneal opacities of early onset, usually between age 5 and 9. Corneal sensitivity is usually reduced, accompanied by pain, photophobia, foreign body sensation, and recurrent erosions.
• MCD type I Virtual absence of keratan sulfate in serum and cornea, determined by KS-specific antibodies–due to a homozygous missense mutation
• MCD type II Normal KS-antibody response in cornea and serum–due to a large deletion and replacement in the upstream region of CHST6.
Molecular pathology Defects in CHST6, which encodes a sulfotransferase that maintains corneal transparency, cause macular corneal dystrophy
Synonyms Corneal dystrophy—macular type, Groenouw type corneal dystrophy