In summary, the pedigree with parents heterozygous for c.538-33C > A of the RYR1 gene did not develop hydrops, whereas the two hydrops fetuses examined were both heterozygous; therefore, we suggest that the c.538-33C > A heterozygous mutation of the RYR1 gene, which affects the normal splicing of the mRNA, may contribute to the development of hydrops in the fetus. Here, RYR1 is linked to edema.