Phenotypic expansion of POGZ-related intellectual disability syndrome (White-Sutton syndrome).

White-Sutton syndrome (WHSUS) is a recently-identified genetic disorder resulting from de novo heterozygous pathogenic variants in POGZ. Thus far, over 50 individuals have been reported worldwide, however phenotypic characterization and data regarding the natural history are still incomplete. Here we report the clinical features of 22 individuals with 21 unique loss of function POGZ variants. We observed a broad spectrum of intellectual disability and/or developmental delay with or without autism, and speech delay in all individuals. Other common problems included ocular abnormalities, hearing loss and gait abnormalities. A validated sleep disordered breathing questionnaire identified symptoms of obstructive sleep apnea in 4/12 (33%) individuals. A higher-than-expected proportion of cases also had gastrointestinal phenotypes, both functional and anatomical, as well as genitourinary anomalies. In line with previous publications, we observed an increased body mass index (BMI) z-score compared to the general population (mean 0.59, median 0.9; p 0.0253). Common facial features included microcephaly, broad forehead, midface hypoplasia, triangular mouth, broad nasal root and flat nasal bridge. Analysis of the Baylor Genetics clinical laboratory database revealed that POGZ variants were implicated in approximately 0.14% of cases who underwent clinical exome sequencing for neurological indications with or without involvement of other body systems. This study describes a greater allelic series and expands the phenotypic spectrum of this new syndromic form of intellectual disability and autism.

Spastic Diplegia in a Haitian Girl with Angelman Syndrome.

Spastic diplegia, a muscle hypertonia motor syndrome, can occur in conjunction with the characteristic abnormal movement features of Angelman syndrome (AS), a neurodevelopmental disorder with primary features of ataxic gait, happy demeanor, developmental delay, speech impairment, intellectual disability, microcephaly, and seizures. Spastic diplegia is classically associated with cerebral palsy (CP), an umbrella term encompassing developmental delay, abnormal brain magnetic resonance imaging findings, and various types of CP including spastic, ataxic, dyskinetic, and mixed types. We present a 12-year-old Haitian patient of African descent with AS due to a microdeletion involving the entire UBE3A (ubiquitin-protein ligase E3A) gene and spastic diplegia. She was initially given a clinical diagnosis of CP. Cases of AS in patients of African descent have been rarely reported and this case of severe spastic diplegia, unresponsive to medical intervention, reflects a rarely reported presentation of AS in patients of African descent and possibly the first reported case of a Haitian patient with this clinical presentation. Given that deletions are the most common mechanism resulting in AS, this case report provides supportive evidence that chromosome 15q11 deletion-type AS is most frequently associated with spastic diplegia, a more severe motor impairment phenotype in AS.