Williams syndrome in a preterm infant with phenotype of Alagille syndrome.

We report on a preterm infant born at 31 weeks of gestation with a phenotype suggestive of Alagille syndrome, yet microarray analysis identified a deletion on 7q11.23 at the Williams syndrome locus. The infant died on day 18 of life with overwhelming sepsis. This case illustrates the importance of microarray analysis in diagnosing genetic conditions, especially in preterm babies whose facial and other clinical manifestations have not fully developed.