Noonan et al. (2003) reported their findings in 73 adults over 21 years of age with Noonan syndrome. In 30%, adult height was in the normal range between the 10th and 90th percentiles. More than half of the females and nearly 40% of males had an adult height below the third percentile. The presence or severity of heart disease was not a factor, and none of the adults with normal height had been treated with growth hormone. Serial measurements of height over many years through childhood to adulthood were available in only a few patients, but their pattern of growth suggested that catch up may occur in late adolescence. The possible benefit of growth hormone therapy could not be evaluated.