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.