Progressive brain atrophy in Schinzel-Giedion syndrome with a SETBP1 mutation

Schinzel-Giedion syndrome is a rare congenital malformation syndrome. Recently, SETBP1 was identified as the causative gene. Herein, we present a Japanese boy with Schinzel-Giedion syndrome resulting from a novel mutation in SETBP1 in order to establish the clinical features and serial MRI findings associated with the syndrome. On the third day of life, the boy was referred to our hospital because of facial abnormalities and feeding difficulty. Midfacial retraction, frontal bossing, deep groove under the eyes, upturned nose, low-set ears, bilateral cryptorchidism, and generalized hypertrichosis were identified on admission. At the age of 7 months, epileptic spasms in series occurred. Based on characteristic facial and skeletal abnormalities and severe developmental delay, we clinically diagnosed him with Schinzel-Giedion syndrome. Direct sequencing of the SETBP1 gene revealed a heterozygous mutation (p.Ile871Ser) in exon 4. Although neither cardiac defect nor choanal stenosis were present in our case, the phenotype of our case was nearly identical to those of previously reported cases confirmed by genetic analysis. Serial MRI from the age of 1 month-3 years revealed progressive brain atrophy, especially in the white matter and basal ganglia. However, myelination was age-appropriate and no obvious abnormal signals in the white matter were seen. Diffusion weighted imaging revealed no abnormal findings. Accumulation of MRI data including diffusion weighted imaging from Schinzel-Giedion syndrome cases is needed to understand the mechanism underlying progressive brain atrophy in this syndrome.