Developmental Outcomes of School-Age Children with Duarte Galactosemia: A Pilot Study

Duarte galactosemia (DG) is a mild allelic variant of classic galactosemia that results from partial impairment of galactose-1P uridylyltransferase (GALT). Although infants with DG are detected by newborn screening in some US states at close to 1/4,000 live births, most are discharged from follow-up very early in life and there is no consensus on whether these children are at increased risk for any of the long-term developmental delays seen in classic galactosemia. There is also no consensus on whether infants with DG benefit from dietary restriction of galactose. Reflecting the current uncertainty, some states choose to identify infants with DG by newborn screening and others do not. As a first step toward characterizing the developmental outcomes of school-age children with DG, we conducted a pilot study, testing 10 children with DG and 5 unaffected siblings from the same group of families. All children tested were between 6 and 11 years old. We used standardized direct assessments and parent-response surveys to collect information regarding cognition, communication, socio-emotional, adaptive behavior, and physical development for each child. Despite the small sample size, our data demonstrated some notable differences between cases and controls in socio-emotional development, in delayed recall, and in auditory processing speed. These results confirm that direct assessment of school-age children with DG can detect subtle but potentially problematic developmental deficits, and underscore the need for a larger study which has sufficient power to evaluate these outcomes while controlling for potentially confounding factors.