Gross and Fine Motor Development in 45,X and 47,XXX Girls

Abstract

Neuromuscular deficits have been described in 47,XXY and 47,XYY boys, but gross and fine motor development of girls with sex chromosome aneuploidy has not been extensively studied. Twenty-one propositae 8 to 19 years of age, identified through newborn screening to be 45,X, 47,XXX, or 45,X mosaic, and 11 control girls were evaluated by a physical therapist unaware of their genetic constitution. The Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) was administered, and the quality of neuromuscular function was determined. The 45,X and 47,XXX propositae exhibited both gross and fine motor dysfunction, with 12 of 15 BOTMP composite scores below the 10th percentile. The clinical assessment confirmed the BOTMP findings, with 13 propositae exhibiting dysfunctional sensory-motor integration. A delay in the age of independent walking confirmed the consistency of motor developmental dysfunction throughout time. Sex chromosome mosaics were more similar to control girls. The gross and fine motor delays were frequently associated with a moderate to severe language dysfunction which adversely affected classroom performance. Regular developmental assessments of children with sex chromosome aneuploidy, including sensory-motor integration, should assist in the identification of early developmental delays and permit appropriate intervention.