Rett syndrome as a minicolumnopathy.

OBJECTIVE

Rett syndrome is a progressive neurological disorder affecting primarily females. It is characterized by the early regression of acquired language, cognitive functions, social skills, and purposeful hand function. Patients with Rett syndrome are often misdiagnosed as autistic. Recent reports of minicolumnar abnormalities in the brains of autistic and Asperger's syndrome prompted us to search for similar pathology in Rett syndrome.

MATERIAL: The patient population consisted of 5 Rett syndrome patients (mean age = 14.4 +/- 4.0 years) and 17 controls (mean age = 14.6 +/- 9.5 years). Tissue was celloidin embedded, sectioned at 35 um and Nissl stained. Images (100x) were taken from Brodmann's areas 9, 21, and 22 from layer III of the left hemisphere.

METHOD: Columnar width measurements for these images were obtained with computerized image analysis using previously published algorithms. Each area was analyzed separately with univariate ANOVA, including diagnosis as a fixed factor and age (linear and quadratic terms), and sex as covariates.

RESULTS

Diagnosis dependent effects were statistically significant only in area 21 (p = 0.009) even when taking into account a Bonferroni correction for the multiple comparisons.

CONCLUSION

Both the regional nature of the changes as well as differences in mean cell spacing differentiates the abnormal minicolumnar morphometry of Rett syndrome from that of autism.