Applications of the pattern variability index (sigma z) to the quantification of dysmorphogenesis in the hand.

We have generated percentiles for the pattern variability index (sigma z) of the hand in 1,088 normal infants, children, and adults and have analyzed pattern variability indices for 820 individuals representing 50 congenital malformation syndromes with respect to the normal percentiles. The majority of the affected individuals exhibited elevated sigma z values for the hand, some vastly in excess of normal, while such syndromes as Down, Turner, and the Prader-Willi syndrome were low rather than high in pattern variability of the hand.