In a study on macrocephaly associated with the DICER1 syndrome, the number of subjects with a head occipitofrontal circumference above the 97th percentile was significantly higher in patients with DICER1 PVs (28/67, 42%) than in family controls (5/43, 12%) [92]. The gene discussed is DICER1; the disease is DICER1-related tumor predisposition.