Contributor: Gordon K. Klintworth
Knobloch syndrome (retinal detachment and occipital encephalocele, OMIM #267750) is inherited syndrome that was first documented by Knobloch and Layer in 1971. The condition, which probably has an autosomal recessive mode of inheritance, was initially described in 5 of 10 siblings of  unaffected  parents and characterized by high myopia [myopia - high], vitreoretinal degeneration, retinal detachment and an occipital encephalocele. Because affected persons were of normal intelligence the encephalocele may have been a meningocele rather than a menigoencephalocele. Some patients may have a congenital occipital scalp defect rather than an encephalocele. Other associated abnormalities that have been found in some cases include abnormal lymphatic vessels in the lung, a patent ductus arteriosus, a single umbilical artery, pyloric stenosis, a defect of the anterior midline scalp and scimitar syndrome. Knochloch syndrome is due to a mutation in the COL18A1 gene. The differential diagnosis includes HARDħE syndrome and Meckel syndrome.