The disorder is progressive, degenerative and fatal, extremely rare worldwide – with approximately 60 official cases reported by 1982.
[4] The development of children born with INCL is normal for the first 8–18 months, but will then flounder and start to regress both physically and mentally.
Motor skills and speech are lost, and optic atrophy causes blindness.
Physiotherapy helps affected children retain the ability to remain upright for as long as possible, and prevents some of the pain.
[citation needed] Recent attempts to treat INCL with cystagon have been unsuccessful.