Expanding the Phenotypic Spectrum of DPH2-Related Disorder.

Biallelic variants in DPH2 have recently been reported to cause the syndrome of developmental delay with short stature, dysmorphic facial features, and sparse hair-2, also known as diphthamide deficiency syndrome-2. Here we report a child with a biallelic loss-of-function variant p.(Arg477*) in DPH2 with clinical features of developmental delay, failure to thrive, sparse hair, seizures that responded to antiepileptics, proportionate short stature, dysmorphism, and hypotonia. Neuroimaging abnormalities were cerebral atrophy, periventricular white matter hyperintensities, and prominent subarachnoid spaces. The electroencephalogram was suggestive of modified hypsarrhythmia. The phenotype of the current case overlaps with the previous cases reported in the literature; however, seizures, behavioral issues, and neuroimaging abnormalities have not been reported to date. This is the third report from the world. The current report gives a detailed account of an Indian child with a DPH2-related disorder.