Smyth C, Kalsi G, Brynjolfsson J, O'Neill J, Curtis D, Rifkin L, Moloney E, Murphy P, Sherrington RS, Petursson H, Gurling HMD. Further tests for linkage at the tyrosine hydroxylase gene locus on chromosome 11p15 in a new sample of British multiplex manic depression (bipolar and unipolar affective disorder) families. Am J Psych 1996 153: 271-274.

Objective: To confirm or refute the previous reports of linkage between affective disorder and polymorphic DNA markers at or near the gene for tyrosine hydroxylase, TH.

Method: Our previous analysis of linkage to TH in 6 Icelandic families was extended to a new sample of 17 multiply affected British families using a tetranucleotide repeat polymorphism at the TH locus.

Results: We report lod scores under the assumption of locus heterogeneity of between 1.2 and 1.4 at TH that persist across three diagnostic models.

Conclusion: These results provide some support for linkage to this region and suggest that additional linkage and association studies should be conducted to determine whether TH or a nearby locus does indeed contribute to susceptibility to manic depression in some families.