GNAS1 gene mutations cause the McCune-Albright syndrome. Some patients may develop unusual, severe, nonendocrine manifestations that may lead to death. We postulate that some cases of sudden infant death syndrome (SIDS) might be caused by GNAS1 gene mutations affecting vital organs. We studied two GNAS1 gene mutations (R201H and R201C) by allele specific PCR and enzymatic digestion in pulmonary, pancreas, liver, kidney, and heart tissue from 29 infants who suffered SIDS. The infants died at age 96 +/- 78 days. At the time of death, children had a height Z score of -0,04 +/- 0,95, a weight Z score of 0,04 +/- 0,91, and a weight for length Z score of 0,1 +/- 0,83. The molecular study by both techniques did not reveal any GNAS1 mutations in the tissues examined. We conclude that GNAS1 gene mutations do not appear to be present in tissues of infants with SIDS.