37

The main clinical characteristics of Soto's Syndrome (cerebral gigantism) have been well defined since their original description in 1964. These patients are of large size at birth and grow quickly during early childhood. They also exhibit macrocephaly, peculiar facies and have developmental delay. The cause of the accelerated growth in these patients has not been elucidated. We studied 17 patients with Soto's Syndrome and found that all of them had macrocephaly, 94% had developmental delay, 59% had large hands and feet, 47% had hypertelorism, 29% had frontal bossing, 24% had high arched palate and 12% had a high hair implantation, prominent jaw and antimongoloid slant of the eyes. Forty percent of our patients had a birth length above the 90 percentile and all had a head circumference above the 95 percentile at birth. Results are shown in the Table, including 6 patients in which we were able to measure the circulating levels of IGF-I (RIA) and IGFBP-3 (IRMA). Fifty percent of our patients (3/6) had IGF-I > 2SD and the 66% of these had IGFBP-3 > 2SD above the Chilean mean for a control population matched by age and socioeconomic status. We conclude that the accelerated growth of some patients with Soto's Syndrome may be related to increased concentrations of IGF-I and IGFBP-3.

Table 1 No caption available.
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