In order to determine the parent-of-origin of the SMAD4 DNM in subjects with sporadic MYHRS, we collected DNA samples from 22 family trios and used a haplotyping strategy relying on the presence of an informative single-nucleotide polymorphism (SNP) in the vicinity of the DNM to distinguish the two parental alleles. This evidence concerns the gene SMAD4 and Myhre syndrome.