MLH1 and schizophrenia: In the neuropsychiatric field, variation in the MMR gene MLH1 has been associated with autism, schizophrenia and lithium-responsive bipolar disorder (Autism Spectrum Disorders Working Group of The Psychiatric Genomics Consortium, 2017; Ripke et al., 2014; Song et al., 2016), while the broader DDR has been implicated in frontotemporal dementia (Ferrari et al., 2017).