Chronic nephritis, sensorineural deafness, growth and developmental retardation, hyperkinesis, and cleft soft palate...

A 5-year-old Japanese boy showed nephritis similar to, but distinct from, that in Alport syndrome. Nephrotic syndrome without hematuria was noticed at age 2, although renal biopsy at age 4 revealed widespread irregular thickening of the glomerular basement membrane with splitting of the lamina densa on electron microscopy, characteristic of nephritis in Alport syndrome. Sensorineural deafness was noticed at age 4 weeks by no auditory brain stem response, unusually early for Alport syndrome. Goodpasture antigen and amyloid P component were found in the glomerular basement membrane. Thus, the antigenicity of the glomerular basement membrane was different from that in male patients with X-linked Alport syndrome. In addition, growth and developmental retardation, hyperkinesis, and cleft soft palate were seen. These features are a hitherto undescribed combination. The family history was negative for any of the features of the boy.