VISUOMOTOR PERFORMANCE IN CHILDREN WITH INFANTILE NEPHROPATHIC CYSTINOSIS

Infantile nephropathic cystinosis is a genetic metabolic disorder in w hich the amino acid cystine accumulates in various organs, including t he kidney, cornea, thyroid, and brain. Despite normal intellect, indiv iduals with cystinosis may have specific impairments in the processing of visual information. To examine further the specific types of defic its in visual processing found in individuals with cystinosis, we admi nistered the Developmental Test of Visual-motor Integration to 26 chil dren with cystinosis (4 to 16 yr, old) and 26 matched controls. The cy stinosis group achieved a significantly lower standard score, raw scor e, and mean ceiling than did the control group. Qualitative analyses s howed that in the cystinosis group, size within errors and rotation er rors were more prevalent than in the control group. Correlational anal yses showed that with advancing age, the cystinosis subjects tended to fall further behind their chronological age, Our data, together with the findings of previous studies, suggest that the visuospatial diffic ulties in children with cystinosis may be due to inadequate perception or processing of visually presented information. Furthermore, the inc reasing discrepancy with age may reflect a progressive cognitive impai rment, possibly as a result of cystine accumulation in the brain over time.