Unique profile of academic learning difficulties in Wiedemann-Steiner syndrome

Five years of experience in the Epigenetics and Chromatin Clinic: what have we learned and where do we go from here?

The multidisciplinary Epigenetics and Chromatin Clinic at Johns Hopkins provides comprehensive medical care for individuals with rare disorders that involve disrupted epigenetics. Initially centered on classical imprinting disorders, the focus shifted to the rapidly emerging group of genetic disorders resulting from pathogenic germline variants in epigenetic machinery genes. These are collectively called the Mendelian disorders of the epigenetic machinery (MDEMs), or more broadly, Chromatinopathies. In five years, 741 clinic visits have been completed for 432 individual patients, with 153 having confirmed epigenetic diagnoses. Of these, 115 individuals have one of 26 MDEMs with every single one exhibiting global developmental delay and/or intellectual disability. This supports prior observations that intellectual disability is the most common phenotypic feature of MDEMs. Additional common phenotypes in our clinic include growth abnormalities and neurodevelopmental issues, particularly hypotonia, attention-deficit/hyperactivity disorder (ADHD), and anxiety, with seizures and autism being less common. Overall, our patient population is representative of the broader group of MDEMs and includes mostly autosomal dominant disorders impacting writers more so than erasers, readers, and remodelers of chromatin marks. There is an increased representation of dual function components with a reader and an enzymatic domain. As expected, diagnoses were made mostly by sequencing but were aided in some cases by DNA methylation profiling. Our clinic has helped to facilitate the discovery of two new disorders, and our providers are actively developing and implementing novel therapeutic strategies for MDEMs. These data and our high follow-up rate of over 60% suggest that we are achieving our mission to diagnose, learn from, and provide optimal care for our patients with disrupted epigenetics.

Associations Between Executive Functioning, Behavioral Functioning, and Adaptive Functioning Difficulties in Wiedemann-Steiner Syndrome

OBJECTIVES

Wiedemann-Steiner syndrome (WSS) is a neurogenetic disorder caused by heterozygous variants in KMT2A. Recent investigations suggest increased anxiety and behavior regulation challenges among those with WSS although the neurobehavioral phenotype remains largely unknown. This study aims to examine the pattern of and associations between executive functioning (EF) and behavior functioning among those with WSS.

METHOD

This study involved utilizing caregiver-report inventories (Behavior Rating Inventory of Executive Function 2nd Edition, BRIEF-2; Adaptive Behavior Assessment 3rd Edition, ABAS-3; Strengths and Difficulties Questionnaire, SDQ) to assess day-to-day behavior functioning among those with WSS (N = 24; mean age = 10.68 years, SD = 3.19). Frequency of clinical elevations in daily difficulties in EF, adaptive behaviors, and behavior regulation were reported. Correlations and hierarchical linear regressions were used to determine the relationships between EF with behavior and adaptive functioning.

RESULTS

Out of our sample, 63% met clinical levels of executive functioning difficulties on the BRIEF-2, and 75% with Hyperactivity and 54% with Emotional Problems on the SDQ. In addition, 33% were rated >2 SD below the normative mean in overall adaptive functioning on the ABAS-3. Elevated ratings in BRIEF-2 Shift, reflective of challenges with mental flexibility, predicted more Emotional Problems and accounted for 33.5% of its variance. More difficulties in Emotional Control were related to greater adaptive deficits, accounting for 33.3% of its variance.

CONCLUSIONS

Those with WSS are at risk for EF deficits, hyperactivity, and emotional dysregulation. EF correlates with adaptive and affective behaviors, highlighting the promise of behavioral interventions to target cognitive flexibility, emotional awareness, and reactivity in this population.

To speak may draw on epigenetic writing and reading: Unravelling the complexity of speech and language outcomes across chromatin-related neurodevelopmental disorders

Speech and language development are complex neurodevelopmental processes that are incompletely understood, yet current evidence suggests that speech and language disorders are prominent in those with disorders of chromatin regulation. This review aimed to unravel what is known about speech and language outcomes for individuals with chromatin-related neurodevelopmental disorders. A systematic literature search following PRISMA guidelines was conducted on 70 chromatin genes, to identify reports of speech/language outcomes across studies, including clinical reports, formal subjective measures, and standardised/objective measures. 3932 studies were identified and screened and 112 were systematically reviewed. Communication impairment was core across chromatin disorders, and specifically, chromatin writers and readers appear to play an important role in motor speech development. Identification of these relationships is important because chromatin disorders show promise as therapeutic targets due to the capacity for epigenetic modification. Further research is required using standardised and formal assessments to understand the nuanced speech/language profiles associated with variants in each gene, and the influence of chromatin dysregulation on the neurobiology of speech and language development.