Barth syndrome is associated with a cognitive phenotype.

OBJECTIVE Barth syndrome is a rare, X-linked recessive disorder that affects only boys. The cardinal characteristics include growth retardation, cardioskeletal myopathy, chronic or cyclic neutropenia, and 3-methylglutaconic aciduria. A preliminary study of five young boys with Barth syndrome suggested a distinct cognitive phenotype. METHODS The present study was designed to explore whether additional evidence for a cognitive phenotype emerged from a larger sample. A psychoeducational assessment battery was administered to 15 boys with Barth syndrome. Data from these boys were compared to data from 15 typically developing boys individually matched on age and grade in school to each of the 15 boys with Barth syndrome. RESULTS Although boys with Barth syndrome had age-appropriate performance on all measures of reading-related skills, their performance on mathematics and visual spatial tasks was significantly lower than that of boys in the comparison group. Moreover, specific aspects of visual short-term memory also differed from available norms. CONCLUSION Our findings support the validity of the preliminary findings and reflect a higher incidence of cognitive difficulties in boys with Barth syndrome relative to boys in the comparison group. Coupled with the fatigue regularly experienced by boys with Barth syndrome, our findings indicate that educational support should be implemented during the early school-age years for children with Barth syndrome.