Chromosomal aberrations in cerebral visual impairment

Abstract

Background: Cerebral visual impairment (CVI) is a disorder in projection and/or interpretation of the visual input in the brain and accounts for 27% of the visually impaired children.

Aim: A large cohort of patients with CVI was investigated in order to ascertain the relevance of chromosomal aberrations in the etiology of this disorder.

Methods: 607 patients with CVI and a visual acuity ≤0.3 were assessed for the presence of a chromosomal aberration retrospectively. The observed aberrations were classified for pathogenicity.

Results: A total of 98 chromosomal aberrations were found in 79 persons (13%) of the cohort. In nine persons it was not possible to classify the clinical implication of the aberration, due to lack of detailed information. In 70 persons it was possible to classify the aberration for causality: in 41 patients the aberration was associated with CVI, in 16 it was unknown and in 13 the aberration was unlikely to be associated with CVI. For four aberrations, present in 26 patients, the association with CVI has been reported before: trisomy 21, 1p36 deletion syndrome, 17p13.3 deletion syndrome (Miller-Dieker syndrome) and 22q13.3 deletion syndrome (Phelan-McDermid syndrome). The chromosomal aberrations in another 15 patients were for the first time associated with CVI.

Conclusions: Chromosomal aberrations associated with CVI were found in 7% (41/607) of patients, of which 37% (15/41) have not been reported before in association with CVI. Therefore, in patients with CVI chromosomal investigations should be routinely performed to warrant a good clinical diagnosis and counseling.

Keywords: Aneuploidy; Cerebral visual impairment; Chromosomal aberrations; Copy number variations; Genetic.