The primary symptom of Norrie Disease (ND) is blindness in male infants, at birth or soon after birth. Secondary symptoms are equally serious, and include progressive hearing loss leading to profound deafness in late adulthood (this affects almost all individuals with ND), and mental problems such as cognitive impairment and autistic traits (this affects up to 30-50% of individuals). Other secondary symptoms which are seen in some cases of ND are epilepsy, seizures, leg ulcers, erectile dysfunction, growth failure, and endocrine abnormalities. The range and severity of symptoms varies, even amongst members of the same family.
The gene associated with the syndrome is located on the X chromosome, and was identified in 1992 in the lab of Prof. Dr. Wolfgang Berger, Institute of Medical Molecular Genetics, University of Zurich.
