Furthermore, there is an occasional parental consanguinity. Several cases point to Dubowitz syndrome occurring in monozygotic twins, siblings, and cousins.[5] There is considerable phenotypic variability between cases, especially in regards to intelligence.[6] Although considerable evidence points to the genetic basis of this disorder, the phenotypic similarity is found infetal alcohol syndrome. Further studies need to be done to determine whether this environmental agent has an effect on the expression of the genotype.[7] Breakdown of chromosomes is known to occur.[5]