22q11.2DS deletion syndrome: developmental milestones in infants and toddlers.

Background: The majority of children with 22q11.2DS deletion syndrome (22q11.2DS) have learning disabilities, and a substantial number have mental retardation. Although cognitive data have been reported on several samples of children with 22q11.2DS, data on their early developmental milestones are limited.

Methods: The present study used a retrospective design and asked parents to recall developmental milestones. The participants were 88 children with 22q11.2DS, 47 community controls, and 29 sibling controls.

Results: Although very early gross motor and expressive language milestones did not differ significantly from comparison groups, subsequent gross motor and expressive language milestones did, suggesting that children with 22q11.2DS may begin to lag behind their peers sometime after the first year of life in these two domains. These patterns were also apparent when a subset of intellectually comparable children (22q11.2DS, n = 40 vs community controls, n = 24) was analyzed. We further found that receptive language and social adaptive milestones did not differ from comparison samples in either the early or later period. Receptive language delays were predictive of later Wechsler Intelligence Scale for Children-Third Edition Perceptual Organization Index scores, particularly in girls with 22q11.2DS.

Conclusions: This suggests that although receptive language may be an area of relative strength in the developmental profile of young children with 22q11.2DS, even mild receptive delays should not be overlooked in early interventions with children with this disorder.