TBL1XR1 associated intellectual disability, a new missense variant with dysmorphic features plus autism: Expanding the phenotypic spectrum.

Missense and frameshift pathogenic variants and microdeletions involving TBL1XR1 gene have been described in patients with intellectual disability, autism, Rett-like features and schizophrenia, some of them with the clinical diagnosis of Pierpont syndrome, a rare pattern of multiple congenital anomalies, but others without dysmorphic findings or with non-specific ones, and also patients with only some of the features associated with Pierpont syndrome. We here present a case with a de novo novel missense variant in TBL1XR1 gene with overlapping features with Pierpont syndrome and autism, a neurobehavioral manifestation not previously reported in Pierpont syndrome. This patient expands the phenotypic spectrum of TBL1XR1 gene pathogenic variants.