Minor morphological aberrations in children with isolated urinary tract malformations.

The prevalence of 54 minor morphological aberrations (MMAs) (mild malformations, dysplasias, deformities and phenogenetic variants) was determined in 138 children with isolated malformations of the urinary tract and in 32 patients with multiple major birth defects including renal malformations. Children with infectious diseases matched to each patient by sex, age and ethnic origin served as controls. The overall prevalence of MMAs--expressed as MMA/subject ratio--proved to be significantly higher in patients with multiple malformations (2.50) than in those with isolated renal abnormalities (0.80) and in controls (0.76). The difference between the latter two groups was not significant. Apart from characteristic patterns of well-defined syndromes, the only specific association found was the higher prevalence of supernumerary nipples in patients with isolated (and hidden) urinary tract abnormalities of various types (9.4% versus 1.8% in controls; P less than 0.005).