Forebrain overgrowth (fog): a new mutation in the mouse affecting neural tube development.

Forebrain overgrowth, fog, is a spontaneous autosomal recessive mutation in the mouse producing forebrain, lumbo-sacral, and facial defects. The defects appear to result from excessive growth or cellular proliferation leading to abnormalities in neural tube closure. Three unique features of the mutant are: (1) the growth of telencephalon cells into the surrounding mesenchyme, (2) presence of an encephalocele through the midline cleft in some mutants, and (3) dissociation of the tail defect from the caudal neural tube defect. We used an intersubspecific intercross between mice carrying the fog mutation and mice from an inbred Mus musculus castaneus strain (CAST/Ei) to map the fog mutation to mouse Chromosome 10 near D10Mit262 and D10Mit230 in a region with several potential candidate genes.