Color Blindness Not Closely Linked to Bipolar Illness

Linkage between X‐chromosome markers and manic‐depressive illness

“…However, there are also reports of linkage to the Xg blood antigen locus (8), which is generally considered so distant from deutan-protan region on X-chromosome that no intermediate marker can be linked to both loci (9,10). Furthermore, later studies by Gershon et al (11) did not replicate the earlier findings with color blindness. Recently, Risch & Baron (12) have shown that the pooled data in the literature are consistent with a model of genetic heterogeneity where a subgroup of pedigrees have close linkage and the remainder are unlinked.…”

Colour vision impairments in bipolar disorder: A systematic review

“…This review also explored the hypothesis proposing the existence of a singular, prominent gene for BD that resides closely to Protan/Deutan gene arrays located on the X-chromosome. Mendlewicz et al (1979) found their pedigree analysis to support co-transmission of BD and colour blindness while a replication study published by Gershon et al (1979) refuted their conclusion ( Mendlewicz et al, 1979 ; Gershon et al, 1979 ). Criticisms to the former study includes potential sampling bias given the lack of reported inclusion criteria as eight out of 110 BD patients were selected, and that all male probands (the BD patient initially recruited to investigate colour blindness within their family) had colour blindness with majority of the selected families having both colour blindness and BD.…”

“…We excluded 2271 studies due to incongruencies to predetermined inclusion criteria. Of the 95 full-text studies, 90 were excluded leaving 5 included papers ( Fernandes et al, 2017 , 2022 ; Mendlewicz et al, 1979 ; Gershon et al, 1979 ; Oliveira et al, 2022 ). Three articles were cross-sectional studies ( Fernandes et al, 2017 , 2022 ; Oliveira et al, 2022 ), and 2 were case-series assessing linkage analyses ( Mendlewicz et al, 1979 ; Gershon et al, 1979 ).…”

“…Of the 95 full-text studies, 90 were excluded leaving 5 included papers ( Fernandes et al, 2017 , 2022 ; Mendlewicz et al, 1979 ; Gershon et al, 1979 ; Oliveira et al, 2022 ). Three articles were cross-sectional studies ( Fernandes et al, 2017 , 2022 ; Oliveira et al, 2022 ), and 2 were case-series assessing linkage analyses ( Mendlewicz et al, 1979 ; Gershon et al, 1979 ). The country of origins included Brazil (n = 3) ( Fernandes et al, 2017 , 2022 ; Oliveira et al, 2022 ), Belgium (n = 1) ( Mendlewicz et al, 1979 ), and the United States (n = 1) ( Gershon et al, 1979 ).…”

“…Three articles were cross-sectional studies ( Fernandes et al, 2017 , 2022 ; Oliveira et al, 2022 ), and 2 were case-series assessing linkage analyses ( Mendlewicz et al, 1979 ; Gershon et al, 1979 ). The country of origins included Brazil (n = 3) ( Fernandes et al, 2017 , 2022 ; Oliveira et al, 2022 ), Belgium (n = 1) ( Mendlewicz et al, 1979 ), and the United States (n = 1) ( Gershon et al, 1979 ). In these articles, BD-I, BD-II and cyclothymia were diagnosed using the Diagnostic and Statistical Manual of Mental Disorders 5th edition (DSM-5) in 3 articles and Schedule for Affective Disorders and Schizophrenia (SADS) in 2 articles ( Table 1 ) .…”