Fig. 1

A summary of important patients’ clinical features. The proband (III.1) shows mild thoracolumbar scoliosis and hypertrichosis of the upper back (in the cervical region) (a), the cortical thumb and no contractures (b), mild unilateral ptosis of the right eye and low anterior hairline limited to the temporal sides (c, d), and normal feet fingers and toes (e). Selected brain MRI sequences of the index case (III.1) at the age of 5 years: Axial T1-W and coronal T2-W images reveal pachygyria in the frontal area (white arrow) and widened Sylvian fissures (f), axial and coronal T2-W images demonstrate diffuse abnormal signal changes in deep and subcortical white matter areas and cortical thickening especially in frontal area (g-i; red and yellow arrows), axial T1-W image illustrates a hypomyelination pattern of deep white matter with partial myelination of LLIC (Lower Limb of Internal Capsule) (j), sagittal T2-weighted MRI scan casts light on enlarged ventricles and agenesis of the corpus callosum and subcortical band heterotopia (k; purple arrow), coronal T2-weighted shows hypomyelination in the pre-dentate white matter of the cerebellum (l; thick red arrowhead). The second patient (III.4) manifested some important clinical features as in downturned corners of the mouth, wide nasal bridge, relatively short nose, mild micrognathia, a mild prominent forehead with bitemporal hollowing (m), bilateral low-set prominent ears, low anterior hairline in lateral sides, and prominent antitragus (n), limb spasticity and hypogenitalism with micropenis and bilateral cryptorchidism (o), overlapping feet toes (p), normal fingers and palm (q), and mild scoliosis and hypertrichosis of the upper back (r)