Two different presentations of de novo variants of CSNK2B: two case reports

Background Poirier-Bienvenu neurodevelopmental syndrome is a neurologic disorder caused by mutations in the CSNK2B gene. It is mostly characterized by early-onset seizures, hypotonia, and mild dysmorphic features. Craniodigital syndrome is a recently described disorder also related to CSNK2B, with a single report in the literature. Objective To report two unrelated cases of children harboring CSNK2B variants (NM_001320.6) who presented with distinct diseases. Case report Case 1 is a 7-month-old, Caucasian, female patient with chief complaints of severe hypotonia and drug-refractory myoclonic epilepsy, with a likely pathogenic de novo variant c.494A>G (p.His165Arg). Case 2 is a 5-year-old male, Latino patient with craniodigital intellectual disability syndrome subjacent to a de novo, likely pathogenic variant c.94G>T (p.Asp32Tyr). His dysmorphic features included facial dysmorphisms, supernumerary nipples, and left-hand postaxial polydactyly. Conclusion This report suggest that the CSNK2B gene may be involved in the physiopathology of neurodevelopmental disorders and variable dysmorphic features.

Automated summary

This study reports two unrelated cases of children with CSNK2B variants, each presenting with a different disease. Case 1 is a 7-month-old Caucasian female with severe hypotonia and drug-refractory myoclonic epilepsy, harboring a likely pathogenic de novo variant. Case 2 is a 5-year-old Latino male with craniodigital intellectual disability syndrome, carrying a likely pathogenic de novo variant. Both cases had distinct dysmorphic features.