Parietal foramina (PFM) are defects of the human skull vault, characterised by symmetrical, oval defects in the parietal bone situated on each side of the sagittal suture and separated from each other by a narrow bridge of bone. Size decreases with age and an intrafamilial variability is seen (OMIM 168500). It is thought to be a normal variant of skull development and, consequently, a benign entity.¹ Currently, loss of function mutations in two genes encoding homeobox containing transcription factors, MSX2 and ALX4, have been detected in patients with PFM.^2,3 Parietal foramina is classified as type I, caused by MSX2 mutations, and type II, which is caused by ALX4 mutations.

Herein, we report a family with PFM type II in which two members had epilepsy and discuss the importance of neuroimaging findings to determine its possible cause. In addition, we study the variations of clinical expression, with regard to the severity of the epilepsy, in different generations.

The first patient, a boy, was referred at the age of 3 months because of a large bone defect (PFM) identified on physical examination. The mother (22 years old), aunt (25 years old), and grandfather (55 years old) also had PFM, but smaller than the child’s, showing an age related size variation. Molecular analysis, …