Clinical and genetic aspects of Conradi-Hünermann disease. A report of three familial cases and review of the literature.

Most reported cases of Conradi-Hünermann disease are said to be sporadic. The diagnostic radiographic features present in early life tend to disappear with age. Skeletal deformities may persist but are not adequate for diagnosis. It is critical that the examiner look for nonskeletal manifestations of the disease, particularly eye and skin changes, in parents and relatives before assuming that the proband represents a sporadic case. Some of the sporadic cases may also be accounted for by the existence of environmental phenocopies. The proband's mother in the family described in this paper was recognized as a carrier of the gene only after careful eye and skin examination. This observation was particularly important because she was pregnant at the time. Her 16-week-old fetus is the earliest documented example of the disease. Autosomal dominant mode of inheritance is suggested by the familial cases, but the variability of expression could be the result of either genetic or clinical heterogeneity. Sex-influenced factors may account for the different severity of the disease in the two sexes.