The spectrum of growth abnormalities 18q deletions

The objective of this study was to assess the spectrum of growth abnormalit ies in children with 18q deletions. The growth axis of 50 individuals with a cytogenetically and molecularly confirmed 18q deletion was investigated b y determining height, growth velocity, insulin-like growth factor I (IGF-I) , IGF-binding protein-3, bone maturation, and response to pituitary stimula nts of GH. Children with 18q deletions are short; 64% have a height more than -2 SD be low the mean. Affected children also grow slowly; 68% have a growth velocit y more than -1 SD below the mean. Half of the individuals have delayed bone maturation. Growth factors are skewed downward; 72% of the IGF-I values an d 83% of the IGF-binding protein-3 values are below the mean for chronologi cal age. Similarly, 72% of the children had a reduced or absent response to either of the the GH stimulants, arginine and clonidine. In the total grou p of 50 children only 2 were normal for all parameters evaluated. Short stature and poor growth are common features of individuals with 18q d eletions. GH deficiency is common in this cohort of patients and probably p lays a role in the short stature seen in many of the affected individuals.