Possible relationship between ulnar-mammary syndrome and split hand with aplasia of the ulna syndrome.

We describe a 3-generation family in which mother, maternal grandfather, and 2 (male and female) children have variably manifestations of the ulnar-mammary syndrome, including ulnar ray defects, obesity, hypogenitalism, delayed puberty, hypoplasia of nipples and apocrine glands, and a previously undescribed ectopia of upper canines. The index patient also had split-hand appearance on the right due to complete absence of the 4th ray. To our knowledge this is the first documented example of split hand in the ulnar-mammary syndrome. The hand anomaly raises the question of a possible causal relationship between ulnar-mammary syndrome and the split hand with aplasia of the ulna syndrome, as already hypothesized by Lenz [1980].