Figure 3. Axial cerebral T2-weighted magnetic resonance images. A: Patient III-1 from Family 1. Dashed arrow: severe hypoplasia of the anterior commissure. Arrow head: normal posterior commissure. Lower arrow: absence of the pineal gland. B: Normal magnetic resonance imaging (MRI) images. Dashed arrow: normal anterior commissure. Arrow head: normal posterior commissure. Lower arrow: normal pineal gland. C:  Patient IV-3 from Family 2. Dashed arrow: normal anterior commissure. Arrow head: absent posterior commissure. Lower arrow: absent pineal gland.