Speech, language, and feeding phenotypes of SATB2 ‐associated syndrome

VPI Management in SATB2 Syndrome: Use of MRI to Evaluate Anatomy and Physiology in Non-Cleft VPI

This clinical case study describes the velopharyngeal anatomy and physiology in a patient who presented with SATB2-associated syndrome (SAS) and velopharyngeal insufficiency (VPI) in the absence of an overt cleft palate. The clinical presentation, treatment, outcome, and the contribution of anatomical findings from MRI to surgical treatment planning for this rare genetic disorder, SAS, are described. This case study contributes to our current understanding of the anatomy and physiology of the velopharyngeal mechanism in an individual born with SAS and non-cleft VPI. It also details the changes following bilateral buccal myomucosal flaps in this patient.

Behaviours that Challenge in SATB2-associated Syndrome: Correlates of Self-injury, Aggression and Property Destruction

SATB2-associated syndrome (SAS) is a genetic syndrome characterised by intellectual disability, severe speech delay, and palatal and dental problems. Behaviours that challenge (BtC) are reported frequently; however, there is limited research on specific forms of BtC and the correlates of these behaviours. The current study explores correlates of well-defined BtC, self-injury, aggression, and property destruction, in SAS. Eighty-one parents/caregivers of individuals with SAS (53.1% male, Mage 10.12 years) completed questionnaire measures of health, behavioural, emotional, and autism characteristics. Individuals with SAS were grouped based on caregiver responses to the presence or absence of self-injury, aggression, and property destruction on the Challenging Behaviour Questionnaire. Rates of self-injury, aggression and property destruction were 42%, 77% and 49%, respectively. Between-group comparisons were conducted to compare characteristics between behaviour groups. Significantly differing characteristics were entered into separate hierarchical logistic regressions for each form of BtC. Behavioural comparisons indicated variation in the characteristics associated with each behaviour. All hierarchical logistic regression models were significant (p < .001): self-injury (χ2(5) = 38.46, R2 = 0.571), aggression (χ2(4) = 25.12, R2 = 0.414), property destruction (χ2(4) = 23.70, R2 = 0.346), explaining between 34.6% and 57.1% of the variance in behaviour presence. This is the first study to identify correlates of self-injury, aggression, and property destruction in SAS. Variability in the characteristics associated with each behaviour highlights the importance of specificity when examining BtC. Understanding correlates of specific forms of BtC has important implications for informing SAS-associated pathways to behavioural outcomes and the implementation of tailored behavioural interventions.

The dental phenotype of primary dentition in SATB2-associated syndrome: a report of three cases and literature review

BACKGROUND

SATB2-associated syndrome (SAS; OMIM: 612,313) is an autosomal dominant inherited multisystemic disorder caused by several variants of the SATB2 gene. SAS is characterized by intellectual disability, developmental delay, severe speech anomalies, craniofacial anomalies, and dental abnormalities. Here, we report the dental phenotype of primary dentition of three Chinese children with SAS.

CASE PRESENTATION

All three cases with SAS showed intellectual disability, speech and language anomalies, and palate anomalies. For the dental phenotype, all three cases showed macrodontia, crowded dentition, extensive caries, periapical abscesses and fistulas. Radiographs showed the wide-open root apex of deciduous teeth, loss of mandibular second bicuspids, delayed root formation of permanent teeth, rotated teeth, and taurodontism. Sanger sequencing of case 1 showed that there was a heterozygous code shift variation, c1985delT (p.F662Sfs*9) in the SATB2 gene, which has not been reported in literature. Root canal therapy, carious restoration, and teeth extraction were managed promptly, while preventive dental care was given regularly.

CONCLUSIONS

The dental phenotype of primary dentition in SAS may show macrodontia, crowded dentition, severe caries, wide-open root apex of deciduous teeth, loss of mandibular second bicuspids, delayed root formation of permanent teeth, rotated teeth, and taurodontism. Regular oral hygiene instructions and preventive dental care are both required.

The behavioural phenotype of SATB2-associated syndrome: a within-group and cross-syndrome analysis

Background

SATB2-associated syndrome (SAS) is a multisystem neurodevelopmental disorder characterised by intellectual disability, speech delay, and craniofacial anomalies. Although the clinical presentation of SAS is well-delineated, behaviours associated with SAS are less well-defined. Given the varied social profile reported in SAS of a ‘jovial’ predisposition and autistic behaviours, there may be phenotypic overlap with both Angelman syndrome (AS) and non-syndromal autism. This study aimed to describe behaviours in SAS in relation to chronological age and level of ability and contrast aspects of the behavioural phenotype with AS and non-syndromal autism.

Methods

Informant report questionnaire measures of behaviour, emotion, and autism characteristics were completed for 81 individuals with SAS (aged 1–36 years; 43 male). Within-group associations were analysed, and categorical data were compared between pre-school (1–5 years), school-age (6–15 years), and adolescent and adult SAS sub-groups (16 years and over). Cross-syndrome subscale and item-level analyses were conducted for 63 individuals with SAS (aged 1–27 years; 31 male), who were matched according to age and level of ability to 63 individuals with AS (aged 2–25 years; 32 male) and 63 individuals with non-syndromal autism (aged 3–26 years; 53 male).

Results

In SAS, higher rates of overactivity were moderately associated with lower self-help ability, and higher general anxiety scores were reported for males compared with females. Cross-syndrome subscale analyses uncovered several significant differences (p < .01), with comparatively low rates of stereotyped behaviour, overactivity, insistence on sameness and positive affect, and comparatively greater interest and pleasure and compulsive behaviour in individuals with SAS. Item-level analyses revealed a distinct profile of repetitive and autistic behaviours.

Limitations

Developmental analysis was based on a cross-sectional rather than a longitudinal research design, the contribution of pain and sleep to behaviour was not explored, and molecular genetic testing to determine genotype–phenotype behavioural relationships was not possible.

Conclusions

This study highlights the importance of behavioural comparisons to well-delineated groups and the utility of fine-grained item-level analyses to elucidate aspects of behaviour that might be syndrome related or shared across neurodevelopmental disorders. Future research is needed to further describe the distinctive repetitive and autistic behavioural phenotype in SAS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11689-022-09426-0.

A novel mutation of SATB2 inhibits odontogenesis of human dental pulp stem cells through Wnt/β-catenin signaling pathway

BACKGROUND

SATB2-associated syndrome (SAS) is a multisystem disorder caused by mutation of human SATB2 gene. Tooth agenesis is one of the most common phenotypes observed in SAS. Our study aimed at identifying novel variant of SATB2 in a patient with SAS, and to investigate the cellular and molecular mechanism of tooth agenesis caused by SATB2 mutation.

METHODS

We applied whole exome sequencing (WES) to identify the novel mutation of SATB2 in a Chinese patient with SAS. Construction and overexpression of wild-type and the mutant vector was performed, followed by functional analysis including flow cytometry assay, fluorescent immunocytochemistry, western blot, quantitative real-time PCR and Alizarin Red S staining to investigate its impact on hDPSCs and the underlying mechanisms.

RESULTS

As a result, we identified a novel frameshift mutation of SATB2 (c. 376_378delinsTT) in a patient with SAS exhibiting tooth agenesis. Human DPSCs transfected with mutant SATB2 showed decreased cell proliferation and odontogenic differentiation capacity compared with hDPSCs transfected with wild-type SATB2 plasmid. Mechanistically, mutant SATB2 failed to translocate into nucleus and distributed in the cytoplasm, failing to activate Wnt/β-catenin signaling pathway, whereas the wild-type SATB2 translocated into the nucleus and upregulated the expression of active β-catenin. When we used Wnt inhibitor XAV939 to treat hDPSCs transfected with wild-type SATB2 plasmid, the increased odontogenic differentiation capacity was attenuated. Furthermore, we found that SATB2 mutation resulted in the upregulation of DKK1 and histone demethylase JHDM1D to inhibit Wnt/β-catenin signaling pathway.

CONCLUSION

We identified a novel frameshift mutation of SATB2 (c.376_378delinsTT, p.Leu126SerfsX6) in a Chinese patient with SATB2-associated syndrome (SAS) exhibiting tooth agenesis. Mechanistically, SATB2 regulated osteo/odontogenesis of human dental pulp stem cells through Wnt/β-catenin signaling pathway by regulating DKK1 and histone demethylase JHDM1D.

Speech-language profiles in the context of cognitive and adaptive functioning in SATB2-associated syndrome

SATB2‐associated syndrome (SAS) is a neurodevelopmental disorder caused by heterozygous pathogenic variants in the SATB2 gene, and is typically characterized by intellectual disability and severely impaired communication skills. The goal of this study was to contribute to the understanding of speech and language impairments in SAS, in the context of general developmental skills and cognitive and adaptive functioning. We performed detailed oral motor, speech and language profiling in combination with neuropsychological assessments in 23 individuals with a molecularly confirmed SAS diagnosis: 11 primarily verbal individuals and 12 primarily nonverbal individuals, independent of their ages. All individuals had severe receptive language delays. For all verbal individuals, we were able to define underlying speech conditions. While childhood apraxia of speech was most prevalent, oral motor problems appeared frequent as well and were more present in the nonverbal group than in the verbal group. For seven individuals, age‐appropriate Wechsler indices could be derived, showing that the level of intellectual functioning of these individuals varied from moderate–mild ID to mild ID‐borderline intellectual functioning. Assessments of adaptive functioning with the Vineland Screener showed relatively high scores on the domain “daily functioning” and relatively low scores on the domain “communication” in most individuals. Altogether, this study provides a detailed delineation of oral motor, speech and language skills and neuropsychological functioning in individuals with SAS, and can provide families and caregivers with information to guide diagnosis, management and treatment approaches.

SATB2-associated syndrome in adolescents and adults

The goal of this study was to investigate the medical, communication, activities of daily living (ADLs), and mental health concerns affecting adolescents and adults with SATB2-associated syndrome (SAS). A comprehensive questionnaire was administered to the caregivers of 49 individuals 12 years or older with SAS (mean age was 19.4 years, range 12-37 years). For all individuals, medical records, including laboratory results, were reviewed. Most individuals required some degree of assistance for ADLs and none of the adults were able to live independently. Health status was qualified as excellent or very good in 61% of individuals. The most common medical problems were dental anomalies, with a significantly higher frequency of hypotonia and gastroesophageal reflux in younger individuals. Medical and surgical interventions were often required. Sixty-nine percent (n = 33) of individuals spoke 10 or fewer words. Autism (41%), anxiety (37%), and attention deficit disorder (37%) were common with one third of individuals receiving medical treatments for these diagnoses. While medical and developmental problems in individuals with SAS were similar to those previously reported, many of these are persistent into adolescence and adulthood. This study provides better guidance for the challenges facing adults with SAS and their families.

Growth, development, and phenotypic spectrum of individuals with deletions of 2q33.1 involving SATB2

SATB2-Associated syndrome (SAS) is an autosomal dominant, multisystemic, neurodevelopmental disorder due to alterations in SATB2 at 2q33.1. A limited number of individuals with 2q33.1 contiguous deletions encompassing SATB2 (ΔSAS) have been described in the literature. We describe 17 additional individuals with ΔSAS, review the phenotype of 33 previously published individuals with 2q33.1 deletions (n = 50, mean age = 8.5 ± 7.8 years), and provide a comprehensive comparison to individuals with other molecular mechanisms that result in SAS (non-ΔSAS). Individuals in the ΔSAS group were often underweight for age (20/41 = 49%) with a progressive decline in weight (95% CI = -2.3 to -1.1, p < 0.0001) and height (95% CI = -2.3 to -1.0, p < 0.0001) Z-score means from birth to last available measurement. ΔSAS individuals were often noted to have a broad spectrum of facial dysmorphism. A composite image of ΔSAS individuals generated by automated image analysis was distinct as compared to matched controls and non-ΔSAS individuals. We also present additional genotype-phenotype correlations for individuals in the ΔSAS group such as an increased risk for aortic root/ascending aorta dilation and primary pulmonary hypertension for those individuals with contiguous gene deletions that include COL3A1/COL5A2 and BMPR2, respectively. Based on these findings, we provide additional care recommendations for individuals with ΔSAS variants.

miR-187-3p participates in contextual fear memory formation through modulating SATB2 expression in the hippocampus

PURPOSE

When threatened, fear is one of the most important responses that an organism exhibits. The mechanisms involved in forming fear memories include specific neurological structures, neural circuits and detailed molecular interactions.

METHODS

MicroRNAs (miRNAs, small non-coding RNAs) act as endogenous functional small molecules that participate in or interfere with the formation of new fear memory by inhibiting the expression of mRNA targets. MicroRNA-187 (miR-187) is a newly reported miRNA that is related to cancer, but it has not been investigated regarding fear memory formation.

RESULTS

In the present study, we observed a transient reduction in the level of miR-187 in the dorsal hippocampus after a classic contextual fear conditioning (CFC) training. Overexpression of miR-187-3p in the DH using miR-187-3p agomir was detrimental in the formation of CFC memory, whereas downregulation of miR-187-3p using antagomir enhanced the formation of CFC memory. Additionally, utilization of bioinformatic methods and luciferase reporter assay revealed that miR-187-3p targets SATB2, and therefore miR-187-3p agomir can decrease the protein level of SATB2. Furthermore, we determined that SATB2 plays a role in the formation of CFC memory by miR-187-3p, which can be mediated by altering SATB2 expression.

CONCLUSION

Altogether, evidence obtained from both in-vitro and in-vivo experiments indicated that miR-187-3p is involved in CFC memory formation through modulation of SATB2. Our data provides a basis for the potential therapeutic benefits of miR-187-3p/SATB2 in the treatment of anxiety disorders induced from fear memory.

Genetic pathways involved in human speech disorders

Rare genetic variants that disrupt speech development provide entry points for deciphering the neurobiological foundations of key human capacities. The value of this approach is illustrated by FOXP2, a transcription factor gene that was implicated in speech apraxia, and subsequently investigated using human cell-based systems and animal models. Advances in next-generation sequencing, coupled to de novo paradigms, facilitated discovery of etiological variants in additional genes in speech disorder cohorts. As for other neurodevelopmental syndromes, gene-driven studies show blurring of boundaries between diagnostic categories, with some risk genes shared across speech disorders, intellectual disability and autism. Convergent evidence hints at involvement of regulatory genes co-expressed in early human brain development, suggesting that etiological pathways could be amenable for investigation in emerging neural models such as cerebral organoids.