cases, but other manifestations are rare. Histological examination shows infiltration of the meninges with polymorphs. Ocular manifestations occur in 80% of cases and include uveitis (70%), papillary involvement, conjunctivitis, and optical neuritis. If untreated, these may result in blindness (25%). The sensorineural hearing loss occurs in 75%, and tends to be progressive leading to deafness in 20% of cases. Almost all children are remarkably short and have growth delay. Fever is extremely common but inconstant and is most often mild. Anemia is frequent. Other findings that have been reported include macrocephaly (95%), large fontanelle, prominent forehead, flattening of the nasal bridge (saddleback nose), short and thick extremities, and finger clubbing. The liver and/or spleen may be enlarged. Lymph node enlargement may also be present. Later in life, secondary amyloidosis may occur. Delayed puberty and secondary amenorrhoea are not uncommon. Hoarseness due to inflammation of the laryngeal cartilage has also been reported. Causes The disease is caused in 60% of cases by a mutated gene called CIAS1 that is known to be involved in other syndromes that appear somewhat similar, such as Muckle–Wells syndrome and familial cold urticaria. In many patients, the parents do not have the same mutation, indicating the problem was not inherited, even though it is a genetic disease.CIAS1 is involved in controlling the immune system, which is why the mutation leads to out-of-control inflammation. Diagnosis The diagnosis is based on observing the patient and finding the constellation of symptoms and signs described above. A few blood tests help, by showing signs of long standing inflammation. There is no specific test for the disease, though now that the gene that causes the disease is known, that may change. Routine laboratory investigations are non specific: anaemia, increased numbers of polymorphs, an elevated erythrocyte sedimentation rate and elevated concentrations of C-reactive protein are typically all the abnormalities found. Lumbar puncture shows elevated levels of polymorphs (20-70% of cases) and occasionally raised eosinophil counts (0-30% of cases). CSF neopterin may be elevated. The X ray abnormalities are unique and characteristic of this syndrome. These changes include bony overgrowth due to premature ossification of the patella and the long bone epiphyses in very young children and bowing of long bones with widening and shortening periosteal reaction in older ones. Audiometry shows a progressive sensineural deafness. Visual examination shows optic atrophy and an increase in the blind spot. CT is usually normal but