Difference in early development of presumed monozygotic twins with Rett syndrome.
Normal early development has generally been insisted on as an essential criterion for the diagnosis of Rett syndrome. A new set of monozygotic female twins is reported. Twin 1 was considered to be abnormal from birth while delay was not suspected in twin 2 until she was about one year old. Some regression occurred during the second year in both twins, who are now clinically indistinguishable from each other at age 4 years. Other than a slight difference in head circumference at birth, no environmental factor which could account for the clinical difference has been identified.
Bruck
I
I
Department of Pediatrics, Federal University of Parana, Curitiba-Parana, Brazil.
Philippart
M
M
Giraldi
D
D
Antoniuk
S
S
D002675:Child, Preschool; D002658:Developmental Disabilities / Q000235:genetics; D004200:Diseases in Twins / Q000235:genetics*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D015518:Rett Syndrome / Q000235:genetics / Q000503:physiopathology*; D014430:Twins, Monozygotic