GENETIC INHERITANCE IN NON-SYNDROMIC INFANTILE ESOTROPIA
This study aimed to analyze the inheritance pattern of infantile esotropia and to investigate the possible involvement of AHI1 gene.
The experimental group consisted of 14 neurologically normal patients with onset of large angle esotropia prior to 6 months of age. Three unaffected subjects from a family of twins with esotropia formed the familial control group. The main control group consisted of 11 organ donors with no history of strabismus. Familial pedigree charts allowed to assess transmission of strabismus phenotype up to four generations. Genomic DNA was obtained from peripheral blood and PCR amplification of AHI1 gene was performed.
The mean onset of esotropia was 1.78 ± 2.32 months and the mean deviation was 57 ± 8.5 prims diopters. Amplification of AHI1 was observed in all patients in the control group, but not in those with infantile esotropia. Among the patients evaluated, 57% had a family history of strabismus. Genetic inheritance was observed in two families with monozygotic twins, one of them consisted of monozygotic twins with infantile esotropia and a third dizygotic twin without strabismus. AHI1 did not amplify in the 3 unaffected subjects from the triplets’ family that formed the familial control group.
The family inheritance of congenital esotropia could be verified in the individuals analyzed, with manifestation in the first, second and third generations. In addition, the genetic inheritance was observed in female twins and male triplets, with two univitelines presenting esotropia and another dizygotic who did not have strabismus. AHI1 gene may play a role in the pathology of infantile esotropia. Additional research is needed to elucidate the genetic patterns of this disorder.
infantile esotropia, strabismus, genetics
UNIFESP - Sao Paulo - Brasil
Dayane Cristine Issaho, Fabio Ramos de Souza Carvalho, Geraldo Barros Ribeiro, Marcia Keiko Uyeno Tabuse, Linda Carrijo-Carvalho, Denise Freitas