3 hydroxyisobutyric aciduria is characterised by ketoacidotic episodes, cerebral anomalies and facial dysmorphism. It is an organic aciduria that involves valine metabolism. Thirteen cases have been described in the literature so far. Transmission is thought to be autosomal recessive.

Facial contour, as viewed from the front, triangular in shape, with breadth at the temples and tapering to a narrow chin.