Broad spectrum of neuropsychiatric phenotypes associated with white matter disease in PTEN hamartoma tumor syndrome

Clinical Neurologic Features and Evaluation of PTEN Hamartoma Tumor Syndrome: A Systematic Review

BACKGROUND AND OBJECTIVES

PTEN hamartoma tumor syndrome (PHTS) is a well-recognized hereditary tumor syndrome and is now also recognized as a common cause of monogenic autism spectrum disorder. There is a vast spectrum of phenotypic variability across individuals with PHTS, and in addition to neurodevelopmental challenges, patients with PHTS may experience a wide variety of neurologic challenges, many of which have only recently been described. Thus, this systematic review aimed to summarize the breadth of the current knowledge of neurologic conditions in individuals with PHTS.

METHODS

We conducted a systematic review using the MEDLINE and EMBASE databases until January 2023. We included studies that reported neurologic signs, symptoms, and diagnoses in patients with a diagnosis of PHTS. Two independent reviewers extracted data (neurologic diagnoses and patient details) from each study. Case reports, case series, prospective studies, and therapeutic trials were included. We assessed the quality of evidence using the appropriate tool from the JBI, depending on study design.

RESULTS

One thousand nine hundred ninety-six articles were screened, and 90 articles met the inclusion criteria. The majority of the included studies were case reports (49/90, 54%) or small case series (31/90, 34%). Epilepsy secondary to cerebral malformations, neurologic deficits from spinal or cranial arteriovenous malformations, and rare tumors such as dysplastic cerebellar gangliocytoma are among the more severe neurologic features reported across patients with PHTS. One interventional randomized control trial examining neurocognitive endpoints was identified and did not meet its efficacy endpoint.

DISCUSSION

Our systematic review defines a broad scope of neurologic comorbidities occurring in individuals with PHTS. Neurologic findings can be categorized by age at onset in individuals with PTHS. Our study highlights the need for additional clinical trial endpoints, informed by the neurologic challenges faced by individuals with PHTS.

Neuropsychological functioning of adults with PTEN hamartoma tumor syndrome

PTEN hamartoma tumor syndrome (PHTS) might be associated with a distinct cognitive and psychological profile. However, previous studies are limited, predominantly based on small and pediatric cohorts, likely affected by selection bias, and show a broad range of findings. We aimed to characterize the neuropsychological functioning of adults with PHTS. A total of 40 participants, with intellectual disability as exclusion criterium, completed an extensive clinical neuropsychological assessment including cognitive tasks, questionnaires, and a clinical diagnostic interview. The cognitive tasks and questionnaire data were categorized as below and above average based on 1.5 SD. About 80% of participants showed an average level of intelligence. In addition, 30% and 24% of participants scored below average on immediate memory recall and speed of information processing, respectively. Furthermore, about 25% reported above average scores on the majority of the questionnaires, indicating psychological distress, signs of alexithymia, and cognitive complaints. Personality of participants was characterized by inflexibility, social withdrawal, and difficulties in recognizing and describing their own emotions. Adults with PHTS demonstrate a heterogeneous yet distinct neuropsychological profile that is characterized by slower information processing, psychological problems, and specific personality traits. These findings provide directions on how to optimize the care and daily lives of adults with PHTS.

Behavioural, developmental and psychological characteristics in children with germline PTEN mutations: a carer report study

BACKGROUND

PTEN is primarily known as a tumour suppressor gene. However, research describes higher rates of difficulties including intellectual disability and difficulties relating to autism spectrum conditions (ASCs) in people with germline PTEN mutations. Other psychological characteristics/experiences are less often reported and are explored in this study.

METHODS

The parents of 20 children with PTEN mutations completed an online survey exploring adaptive behaviour, ASC-associated behaviours, anxiety, mood, hypermobility, behaviours that challenge, sensory experiences, quality of life and parental wellbeing. Published normative data and data from groups of individuals with other genetic neurodevelopmental conditions were used to contextualise findings.

RESULTS

Overall levels of adaptive behaviour were below the 'typical' range, and no marked relative differences were noted between domains. Higher levels of ASC-related difficulties, including sensory experiences, were found in comparison with 'typically developing' children, with a possible peak in restrictive/repetitive behaviour; ASC and sensory processing atypicality also strongly correlated with reported joint hypermobility. A relative preservation of social motivation was noted. Anxiety levels were found to be elevated overall (and to relate to sensory processing and joint hypermobility), with the exception of social anxiety, which was comparable with normative data. Self-injurious behaviour was common.

CONCLUSIONS

Results suggest a wide range of possible difficulties in children with PTEN mutations, including elevated anxiety. Despite elevated ASC phenomenology, social motivation may remain relatively strong. Firm conclusions are restricted by a small sample size and potential recruitment bias, and future research is required to further explore the relationships between such characteristics.

Imaging findings of children with PTEN-related hamartoma tumor syndrome: a 20-year multicentric pediatric cohort

BACKGROUND

PTEN-related hamartoma tumor syndrome results from a mutation in the PTEN gene located at 10q23.31. This syndrome represents a spectrum of different phenotypes of variable expressions, now recognized as part of the same condition. Patients with this mutation have an increased risk of developing a wide range of findings, including malignancies. Although widely described in adults, there are no large series describing the imaging findings in patients before adulthood. Knowledge of the findings seen in children and adolescents with PTEN-related hamartoma tumor syndrome can help guide further management and improve surveillance recommendations.

OBJECTIVE

To describe the spectrum of imaging abnormalities in pediatric patients with PTEN-related hamartoma tumor syndrome.

MATERIALS AND METHODS

We performed a retrospective, cross-sectional, multicenter study conducted between January 2000 and October 2021 in three tertiary pediatric institutions evaluating the imaging findings in children and adolescents (≤ 18 years) with confirmed diagnoses of a PTEN mutation. For each patient, the imaging findings, histopathology reports, and at least a 2-year follow-up of clinical outcomes for non-operative cases were documented.

RESULTS

The cohort included 78 children (37 girls), with a mean age at diagnosis of 7.5 years (range 0 days to 18 years). Benign brain findings included enlarged Virchow-Robin perivascular spaces, white matter changes, developmental venous anomalies, and cerebellar hamartomas. Benign thyroid findings were common, but 5/45 (11.1%) with thyroid abnormalities had a malignant nodule. Soft tissue adipocytic tumors, GI/GU polyps, other soft tissue abnormalities, along with vascular anomalies in various anatomic locations were common.

CONCLUSION

Brain abnormalities, benign non-vascular soft tissue abnormalities, and vascular anomalies are commonly seen in children and adolescents with PTEN-related hamartoma tumor syndrome. However, malignancies involving the thyroid gland are not uncommon. Familiarity with the phenotype of PTEN-related hamartoma tumor syndrome in the pediatric population can improve diagnosis and prompt appropriate clinical surveillance of abnormal findings that warrant further management.

A New Frameshift Mutation of PTEN Gene Associated with Cowden Syndrome-Case Report and Brief Review of the Literature

Cowden syndrome (CS) is a rare disease that was first described in 1963 and later included in the large group of genodermatoses. It is the most common syndrome among the PTEN-associated hamartomatous tumor syndromes (PHTS). CS has an autosomal dominant inheritance pattern, with increased penetrance and variable expressivity, making early diagnosis difficult. Mutations in the PTEN gene (phosphatase and TENsin homolog) are involved in its pathogenesis, involving many organs and systems originating in the three embryonic layers (ectodermum, endodermum, and mesodermum). The consequence is the development of hamartomatous lesions in various organs (brain, intestines, thyroid, oropharyngeal cavity, colon, rectum, etc.). Multiple intestinal polyps are common in patients with CS, being identified in over 95% of patients undergoing colonoscopy. The authors describe the case of a patient who presented the first signs of the disease at 3 ½ years (tonsil polyp) but was diagnosed only at the age of 20 following a colonoscopy that revealed hundreds of intestinal polyps, suggesting further molecular testing. A heterozygous frameshift mutation was identified in the PTEN gene, classified as a potentially pathogenic variant (c.762del.p(Val255*)). The authors present this case to highlight the path taken by the patient from the first symptoms to the diagnosis and to emphasize the clinical aspects of this mutational variant that have still not been identified in other patients with this syndrome.

Development of informant-report neurobehavioral survey scales for PTEN hamartoma tumor syndrome and related neurodevelopmental genetic syndromes

There are few well-validated measures that are appropriate for assessing the full range of neurobehavioral presentations in PTEN hamartoma tumor syndrome (PHTS) and other neurodevelopmental genetic syndromes (NDGS). As potential therapeutics are developed, having reliable, valid, free, and easily accessible measures to track a range of neurobehavioral domains will be crucial for future clinical trials. This study focused on the development and initial psychometric evaluation of a set of freely available informant-report survey scales for PHTS-the Neurobehavioral Evaluation Tool (NET). Concept elicitation, quantitative ratings, and cognitive interviewing processes were conducted with stakeholders and clinician-scientist experts, used to identify the most important neurobehavioral domains for this population, and to ensure items were appropriate for the full range of individuals with PHTS. Results of this process identified a PHTS neurobehavioral impact model with 11 domains. The final NET scales assessing these domains were administered to a sample of 384 participants (median completion time = 20.6 min), including 32 people with PHTS, 141 with other NDGS, 47 with idiopathic neurodevelopmental disorder (NDD), and 164 neurotypical controls. Initial psychometric results for the total scores of each scale indicated very good model (ω = 0.83-0.99) and internal consistency reliability (α = 0.82-0.98) as well as excellent test-retest reproducibility at 1-month follow-up (r = 0.78-0.98) and stability at 4-month follow-up (r = 0.76-0.96). Conditional reliability estimates indicated very strong measurement precision in key score ranges for assessing PHTS and other people with NDGS and/or idiopathic NDD. Comparisons across domains between PHTS and the other groups revealed specific patterns of symptoms and functioning, including lower levels of challenging behavior and more developed daily living and executive functioning skills relative to other NDGS. The NET appears to be a reliable and potentially useful tool for clinical characterization and monitoring of neurobehavioral symptoms in PHTS and may also have utility in the assessment of other NDGS and idiopathic NDD. Additional validation work, including convergent and discriminant validity analyses, are needed to replicate and extend these observations.

How we approach complex vascular anomalies and overgrowth syndromes

Vascular anomalies, both vascular tumors and vascular malformations, can occur in isolation or as part of syndromes including those which feature phenotypic overgrowth. To update what is known about vascular anomalies associated with overgrowth, PubMed was searched for "overgrowth syndromes and vascular anomalies or malformations." PubMed, OMIM, and the Rare Disease Database also were searched for specific diagnoses. We review individual overgrowth syndromes, provide a case-based approach to the clinical, radiographic, pathologic, and genetic basis for diagnosis, to complications of both the vascular anomalies and the overgrowth, and emphasize the need for a multidisciplinary approach to care.

The impact of phosphorylated PTEN at threonine 366 on cortical connectivity and behaviour

The lipid phosphatase PTEN (phosphatase and tensin homologue on chromosome 10) is a key tumour suppressor gene and an important regulator of neuronal signalling. PTEN mutations have been identified in patients with autism spectrum disorders, characterized by macrocephaly, impaired social interactions and communication, repetitive behaviour, intellectual disability, and epilepsy. PTEN enzymatic activity is regulated by a cluster of phosphorylation sites at the C-terminus of the protein. Here, we focussed on the role of PTEN T366 phosphorylation and generated a knock-in mouse line in which Pten T366 was substituted with alanine (PtenT366A/T366A). We identify that phosphorylation of PTEN at T366 controls neuron size and connectivity of brain circuits involved in sensory processing. We show in behavioural tests that PtenT366/T366A mice exhibit cognitive deficits and selective sensory impairments, with significant differences in male individuals. We identify restricted cellular overgrowth of cortical neurons in PtenT366A/T366A brains, linked to increases in both dendritic arborization and soma size. In a combinatorial approach of anterograde and retrograde monosynaptic tracing using rabies virus, we characterize differences in connectivity to the primary somatosensory cortex of PtenT366A/T366A brains, with imbalances in long-range cortico-cortical input to neurons. We conclude that phosphorylation of PTEN at T366 controls neuron size and connectivity of brain circuits involved in sensory processing and propose that PTEN T366 signalling may account for a subset of autism-related functions of PTEN.

Case Series: Neurobehavioral Profile of Adolescents with PTEN Hamartoma Tumor Syndrome

Background

PTEN Hamartoma Tumor Syndrome (PHTS) is a rare genetic condition caused by germline mutations in the phosphatase and tensin homologue (PTEN) gene with a phenotype that includes macrocephaly, cancer predisposition, developmental delay, increased risk for autism spectrum disorder (ASD), and learning difficulties. Studies characterizing neurobehavioral profiles are limited.

Methods

This single-site, retrospective case series was completed in children who have PHTS followed in a cancer predisposition clinic. Demographic and clinical, data were abstracted from the medical record for 12 patients (mean age at clinic entry = 8.83 years; 42% female). Neuropsychological data were abstracted for 3 of 12 patients that were referred for testing (17-year-old female with attention-deficit/hyperactivity disorder [ADHD]; 15-year-old male with academic concerns and ASD, 12-year-old male with academic concerns).

Results

Of the 12 patients, macrocephaly was present in 100%, 58% had developmental delays during early childhood, and 17% had an ASD diagnosis. Results from neuropsychological testing showed Borderline to Average range global intellectual functioning (Standard Score range: 77 to 95) along with deficits in non-verbal reasoning, visual-motor integration, math achievement, and caregiver-rated adaptive skills.

Conclusion

Individuals with PHTS may present with cognitive difficulties that impact everyday functioning, with or without a neurodevelopmental diagnosis. Routine neurocognitive assessment should be considered in management guidelines.

Brain 18F-FDG PET in Cowden Syndrome

ABSTRACT

Cowden disease is associated with neurodevelopmental abnormalities such as macrocephaly, autism spectrum disorder, and developmental delay. Our understanding of neuroimaging anomalies in patients with PTEN mutations is limited to anatomical MRI abnormalities including white matter abnormalities, meningiomas, arteriovenous malformations, and cortical dysplasia. Our current communication extends the neurological Cowden syndrome phenotype by using brain 18F-FDG PET/CT imaging as a useful complementary approach to MRI to explore movement disorders and neuropsychiatric syndromes in a patient with Cowden disease. Brain 18F-FDG PET/CT showed diffuse hypometabolism of the prefrontal mesial and dorsolateral areas including supplementary motor areas, the pons extended to the cerebellum.

Behavioural and psychological features of PTEN mutations: a systematic review of the literature and meta-analysis of the prevalence of autism spectrum disorder characteristics

BACKGROUND

Phosphatase and tensin homologue (PTEN) is a cancer suppressor gene. Constitutional mutations affecting this gene are associated with several conditions, collectively termed PTEN hamartoma tumour syndromes (PHTS). In addition to hamartomas, PTEN aberrations have been associated with a range of non-tumoural phenotypes such as macrocephaly, and research indicates possibly increased rates of developmental delay and autism spectrum disorder (ASD) for people with germline mutations affecting PTEN.

METHOD

A systematic review of literature reporting behavioural and psychological variables for people with constitutional PTEN mutations/PHTS was conducted using four databases. Following in-depth screening, 25 articles met the inclusion criteria and were used in the review. Fourteen papers reported the proportion of people with PTEN mutations/PTHS meeting criteria for or having characteristics of ASD and were thus used in a pooled prevalence meta-analysis.

RESULTS

Meta-analysis using a random effects model estimated pooled prevalence of ASD characteristics at 25% (95% CI 16-33%), although this should be interpreted cautiously due to possible biases in existing literature. Intellectual disability and developmental delay (global, motor and speech and language) were also reported frequently. Emotional difficulties and impaired cognitive functioning in specific domains were noted but assessed/reported less frequently. Methods of assessment of psychological/behavioural factors varied widely (with retrospective examination of medical records common).

CONCLUSIONS

Existing research suggests approximately 25% of people with constitutional PTEN mutations may meet criteria for or have characteristics of ASD. Studies have also begun to establish a range of possible cognitive impairments in affected individuals, especially when ASD is also reported. However, further large-scale studies are needed to elucidate psychological/behavioural corollaries of this mutation, and how they may relate to physiological/physical characteristics.

A systematic review of brain MRI findings in monogenic disorders strongly associated with autism spectrum disorder

BACKGROUND

Research on monogenic forms of autism spectrum disorder (autism) can inform our understanding of genetic contributions to the autism phenotype; yet, there is much to be learned about the pathways from gene to brain structure to behavior. This systematic review summarizes and evaluates research on brain magnetic resonance imaging (MRI) findings in monogenic conditions that have strong association with autism. This will improve understanding of the impact of genetic variability on brain structure and related behavioral traits in autism.

METHODS

The search strategy for this systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Risk of bias (ROB) assessment was completed on included studies using the Newcastle-Ottawa Scales.

RESULTS

Of 4,287 studies screened, 69 were included pertaining to 13 of the top 20 genes with the strongest association with autism. The greatest number of studies related to individuals with PTEN variants and autism. Brain MRI abnormalities were reported for 12 of the 13 genes studied, and in 51.7% of participants across all 13 genes, including 100% of participants with ARID1B variants. Specific MRI findings were highly variable, with no clear patterns emerging within or between the 13 genes, although white matter abnormalities were the most common. Few studies reported specific details about methods for acquisition and processing of brain MRI, and descriptors for brain abnormalities were variable. ROB assessment indicated high ROB for all studies, largely due to small sample sizes and lack of comparison groups.

CONCLUSIONS

Brain abnormalities are common in this population of individuals, in particular, children; however, a range of different brain abnormalities were reported within and between genes. Directions for future neuroimaging research in monogenic autism are suggested.

Prevalence and clinical/molecular characteristics of PTEN mutations in Turkish children with autism spectrum disorders and macrocephaly

Background

Phosphatase and tensin homolog (PTEN) germline mutations are associated with cancer syndromes (PTEN hamartoma tumor syndrome; PHTS) and in pediatric patients with autism spectrum disorder (ASD) and macrocephaly. The exact prevalence of PTEN mutations in patients with ASD and macrocephaly is uncertain; with prevalence rates ranging from 1% to 17%. Most studies are retrospective and contain more adult than pediatric patients, there is a need for more prospective pediatric studies.

Methods

We recruited 131 patients (108 males, 23 females) with ASD and macrocephaly between the ages of 3 and 18 from five child and adolescent psychiatry clinics in Turkey from July 2018 to December 2019. We defined macrocephaly as occipito‐frontal HC size at or greater than 2 standard deviations (SD) above the mean for age and sex on standard growth charts. PTEN gene sequence analysis was performed using a MiSeq next generation sequencing (NGS) platform, (Illumina).

Conclusion

PTEN gene sequence analyses identified three pathogenic/likely pathogenic mutations [NM_000314.6; p.(Pro204Leu), (p.Arg233*) and novel (p.Tyr176Cys*8)] and two variants of uncertain significance (VUS) [NM_000314.6; p.(Ala79Thr) and c.*10del]. We also report that patient with (p.Tyr176Cys*8) mutation has Grade 1 hepatosteatosis, a phenotype not previously described. This is the first PTEN prevalence study of patients with ASD and macrocephaly in Turkey and South Eastern Europe region with a largest homogenous cohort. The prevalence of PTEN mutations was found 3.8% (VUS included) or 2.29% (VUS omitted). We recommend testing for PTEN mutations in all patients with ASD and macrocephaly.

Fetal Megalencephaly with Cortical Dysplasia at 18 Gestational Weeks Related to Paternal UPD Mosaicism with PTEN Mutation

The phosphatase and tensin homolog (PTEN) gene is a tumor-suppressor gene located on 10q22-23. Since the introduction of molecular genetics in prenatal diagnostics, various birth defects associated with gene mutations have been diagnosed. However, no reports on fetal cases related to PTEN mutation have been found, so far. We encountered a rare case of fetal PTEN mutation. Fetal macrocephaly was noted at 16 weeks. At 18 and 20 weeks, neurosonography revealed megalencephaly with an asymmetrical structure and multifocal polygyria. The head circumference (HC) was +6.2 SD at 18 weeks and +8.1 SD at 20 weeks. The parents opted for pregnancy termination, and the male fetus was delivered at 21 weeks, with HC +9.3 SD. Single-nucleotide polymorphism (SNP) array for amniotic cells showed paternal uniparental disomy (UPD) 10q mosaicism, and the mosaic ratio was calculated as 56% from B-allele frequency. Exome sequencing revealed the pathogenic PTEN mutation with mosaicism. The heterozygous PTEN mutation may not cause early manifestations from the fetal period, and an abnormal phenotype may appear after birth. This may be the reason why fetal defects associated with PTEN mutation are not detected. Since this case had homozygous and heterozygous mutations, survival was possible, exhibiting an incredibly huge head with cortical dysplasia from early pregnancy.

Psychiatric Characteristics Across Individuals With PTEN Mutations

Germline heterozygous PTEN mutations have been associated with high prevalence of autism spectrum disorder (ASD) and elevated rates and severity of broadly defined behavioral problems. However, limited progress has been made toward understanding whether PTEN mutation is associated with specific psychiatric co-morbidity profiles when compared to idiopathic ASD. The current study aimed to utilize a cross-measure approach to compare concurrent psychiatric characteristics across children and adolescents with PTEN mutation with (PTEN-ASD; n = 38) and without ASD (PTEN-No ASD; n = 23), and ASD with macrocephaly but no PTEN mutation (macro-ASD; n = 25) using the Child Behavior Checklist (CBCL) and the Aberrant Behavior Checklist (ABC). There were significant group effects for the CBCL Internalizing and Externalizing broad symptom score, the majority of specific CBCL syndrome scores, and all ABC subscale scores. Post-hoc comparisons revealed greater behavioral symptoms in the ASD groups (PTEN-ASD and macro-ASD) compared to the PTEN-no ASD group on nearly all subtest scores examined. There were no statistically significant differences between the PTEN-ASD and macro-ASD groups; however, there was a trend for the macro-ASD group showing higher levels of aggressive behaviors. Our findings provide evidence of specific behavior profiles across PTEN-No ASD, PTEN-ASD, and macro-ASD groups and highlight the importance of early identification of behavioral vulnerabilities in individuals with PTEN mutations in order to provide access to appropriate evidence-based interventions.

Polymicrogyria is Associated With Pathogenic Variants in PTEN

OBJECTIVE

Congenital structural brain malformations have been described in patients with pathogenic phosphatase and tensin homologue (PTEN) variants, but the frequency of cortical malformations in patients with PTEN variants and their impact on clinical phenotype are not well understood. Our goal was to systematically characterize brain malformations in patients with PTEN variants and assess the relevance of their brain malformations to clinical presentation.

METHODS

We systematically searched a local radiology database for patients with PTEN variants who had available brain magnetic resonance imaging (MRI). The MRI scans were reviewed systematically for cortical abnormalities. We reviewed electroencephalogram (EEG) data and evaluated the electronic medical record for evidence of epilepsy and developmental delay.

RESULTS

In total, we identified 22 patients with PTEN pathogenic variants for which brain MRIs were available (age range 0.4-17 years). Twelve among these 22 patients (54%) had polymicrogyria (PMG). Variants associated with PMG or atypical gyration encoded regions of the phosphatase or C2 domains of PTEN. Interestingly, epilepsy was present in only 2 of the 12 patients with PMG. We found a trend toward higher rates of global developmental delay (GDD), intellectual disability (ID), and motor delay in individuals with cortical abnormalities, although cohort size limited statistical significance.

INTERPRETATION

Malformations of cortical development, PMG in particular, represent an under-recognized phenotype associated with PTEN pathogenic variants and may have an association with cognitive and motor delays. Epilepsy was infrequent compared to the previously reported high risk of epilepsy in patients with PMG. ANN NEUROL 2020;88:1153-1164.

An assessment of the autism neuroimaging literature for the prospects of re-executability

Background: The degree of reproducibility of the neuroimaging literature in psychiatric application areas has been called into question and the issues that relate to this reproducibility are extremely complex. Some of these complexities have to do with the underlying biology of the disorders that we study and others arise due to the technology we apply to the analysis of the data we collect. Ultimately, the observations we make get communicated to the rest of the community through publications in the scientific literature. Methods: We sought to perform a 're-executability survey' to evaluate the recent neuroimaging literature with an eye toward seeing if the technical aspects of our publication practices are helping or hindering the overall quest for a more reproducible understanding of brain development and aging. The topic areas examined include availability of the data, the precision of the imaging method description and the reporting of the statistical analytic approach, and the availability of the complete results. We applied the survey to 50 publications in the autism neuroimaging literature that were published between September 16, 2017 to October 1, 2018. Results: The results of the survey indicate that for the literature examined, data that is not already part of a public repository is rarely available, software tools are usually named but versions and operating system are not, it is expected that reasonably skilled analysts could approximately perform the analyses described, and the complete results of the studies are rarely available.  Conclusions: We have identified that there is ample room for improvement in research publication practices. We hope exposing these issues in the retrospective literature can provide guidance and motivation for improving this aspect of our reporting practices in the future.

An assessment of the autism neuroimaging literature for the prospects of re-executability

Background: The degree of reproducibility of the neuroimaging literature in psychiatric application areas has been called into question and the issues that relate to this reproducibility are extremely complex. Some of these complexities have to do with the underlying biology of the disorders that we study and others arise due to the technology we apply to the analysis of the data we collect. Ultimately, the observations we make get communicated to the rest of the community through publications in the scientific literature. Methods: We sought to perform a 're-executability survey' to evaluate the recent neuroimaging literature with an eye toward seeing if our publication practices are helping or hindering the overall quest for a more reproducible understanding of brain development and aging. The topic areas examined include availability of the data, the precision of the imaging method description and the reporting of the statistical analytic approach, and the availability of the complete results. We applied the survey to 50 publications in the autism neuroimaging literature that were published between September 16, 2017 to October 1, 2018. Results: The results of the survey indicate that for the literature examined, data that is not already part of a public repository is rarely available, software tools are usually named but versions and operating system are not, it is expected that reasonably skilled analysts could approximately perform the analyses described, and the complete results of the studies are rarely available.  Conclusions: We have identified that there is ample room for improvement in research publication practices. We hope exposing these issues in the retrospective literature can provide guidance and motivation for improving this aspect of our reporting practices in the future.

Cerebral MRI and Clinical Findings in Children with PTEN Hamartoma Tumor Syndrome: Can Cerebral MRI Scan Help to Establish an Earlier Diagnosis of PHTS in Children?

Background: PTEN Hamartoma Tumor Syndrome (PHTS) is caused by germline autosomal-dominant mutations of the tumor suppressor gene PTEN. Subjects harbour an increased risk for tumor development, with thyroid carcinoma occurring in young children. Establishing a diagnosis is challenging, since not all children fulfill diagnostic criteria established for adults. Macrocephaly is a common feature in childhood, with cerebral MRI being part of its diagnostic workup. We asked whether distinct cMRI features might facilitate an earlier diagnosis. Methods: We retrospectively studied radiological and clinical data of pediatric patients who were presented in our hospital between 2013 and 2019 in whom PTEN gene mutations were identified. Results: We included 27 pediatric patients (18 male) in the analysis. All patients were macrocephalic. Of these, 19 patients had received at least one cMRI scan. In 18 subjects variations were detected: enlarged perivascular spaces (EPVS; in 18), white matter abnormalities (in seven) and less frequently additional pathologies. Intellectual ability was variable. Most patients exhibited developmental delay in motor skills, but normal intelligence. Conclusion: cMRI elucidates EPVS and white matter abnormalities in a high prevalence in children with PHTS and might therefore aid as a diagnostic feature to establish an earlier diagnosis of PHTS in childhood.

Cowden syndrome complicated by schizophrenia: A first clinical report

Patients with Cowden syndrome exhibit mucocutaneous lesions, hamartomatous polyposis of the gastrointestinal tract, and macrocephaly, often complicated by malignant tumors, such as breast, thyroid, and uterine cancers. Autism spectrum and epilepsy have been known as neuropsychiatric symptoms associated with Cowden syndrome; however, to the best of our knowledge, there is no report on cases complicated by schizophrenia. Here, we report a first case of Cowden syndrome complicated by schizophrenia. A 49-year-old Japanese woman started experiencing auditory hallucinations in her teens. She had left breast cancer at the age of 34 years, and right breast cancer at the age of 37 years, all of which were surgically treated. She was also being treated by oral medications for Hashimoto's disease. On consulting her previous doctor for abnormal uterine bleeding that lasted for a year, she was diagnosed with endometrial cancer. However, immediately before surgery, her auditory hallucinations and paranoid delusions became severe, and she was referred to our hospital for detailed examination and treatment. No abnormalities were found on head MRI, and she was diagnosed with schizophrenia on the basis of neuropsychiatric examination findings. After her psychiatric symptoms were controlled by 2 mg of risperidone, she underwent surgery for endometrial cancer. Although there was no apparent family history, physical findings including macrocephaly and papillomatous skin lesions together with her past medical history of multiple malignant tumors suggested Cowden syndrome. Postoperatively, genetic testing revealed a pathogenic variant c.655C > T; p. Gln219* (NM_000314.4) in PTEN, leading to the confirmation of the diagnosis of Cowden syndrome.

The Role of PTEN in Neurodevelopment

PTEN is a lipid and protein phosphatase that regulates cell growth and survival. Mutations to PTEN are highly penetrant for autism spectrum disorder (ASD). Here, we briefly review the evidence linking PTEN mutations to ASD and the mouse models that have been used to study the role of PTEN in neurodevelopment. We then focus on the cellular phenotypes associated with PTEN loss in neurons, highlighting the role PTEN plays in neuronal proliferation, migration, survival, morphology, and plasticity.

Brain morphological analysis in PTEN hamartoma tumor syndrome

PTEN hamartoma tumor syndrome (PHTS) is a spectrum of hereditary cancer syndromes caused by germline mutations in PTEN. PHTS is of high interest, because of its high rate of neurological comorbidities including macrocephaly, autism spectrum disorder, and intellectual dysfunction. Since detailed brain morphology and connectivity of PHTS remain unclear, we quantitatively evaluated brain magnetic resonance imaging (MRI) in PHTS. Sixteen structural T1-weighted and 9 diffusion-weighted MR images from 12 PHTS patients and neurotypical controls were used for structural and high-angular resolution diffusion MRI (HARDI) tractography analyses. Mega-corpus callosum was observed in 75%, polymicrogyria in 33%, periventricular white matter lesions in 83%, and heterotopia in 17% of the PHTS participants. While gyrification index and hemispheric cortical thickness showed no significant differences between the two groups, significantly increased global and regional brain volumes, and regionally thicker cortices in PHTS participants were observed. HARDI tractography showed increased volume and length of callosal pathways, increased volume of the arcuate fasciculi (AF), and increased length of the bilateral inferior longitudinal fasciculi (ILF), bilateral inferior fronto-occipital fasciculi (IFOF), and bilateral uncinate fasciculus. A decrease in fractional anisotropy and an increased in apparent diffusion coefficient values of the AF, left ILF, and left IFOF in PHTS.

Copy Number Variation and Clinical Outcomes in Patients With Germline PTEN Mutations

IMPORTANCE

PTEN is among the most common autism spectrum disorder (ASD)-predisposition genes. Germline PTEN mutation carriers can develop malignant neoplasms and/or neurodevelopmental disorders such as ASD and developmental delay. Why a single gene contributes to disparate clinical outcomes, even in patients with identical PTEN mutations, remains unclear.

OBJECTIVE

To investigate the association of copy number variations (CNVs), altered numbers of copies of DNA sequences within the genome, with specific phenotypes in patients with germline PTEN mutations.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study examined genome-wide microarrays performed on blood-derived DNA to detect germline CNVs from September 1, 2005, through January 3, 2018. Multicenter accrual occurred from community and academic medical centers throughout North America, South America, Europe, Australia, and Asia. Participants included patients with PTEN hamartoma tumor syndrome (PHTS) (n = 481), molecularly defined as carrying germline pathogenic PTEN mutations. Data were analyzed from November 14, 2018, to August 1, 2019.

EXPOSURES

Detection of CNVs from patient-derived germline DNA.

MAIN OUTCOMES AND MEASURES

Prevalence of pathogenic and/or likely pathogenic CNVs in patients with PHTS and association with ASD/developmental delay and/or cancer, ascertained through medical records and pathology reports.

RESULTS

The study included 481 patients with PHTS (mean [SD] age, 33.2 [21.6] years; 268 female [55.7%]). The analytic series consisted of 309 patients with PHTS and genetically determined European ancestry. Patients were divided into 3 phenotypic groups, excluding family members within each group. These include 110 patients with ASD/developmental delay, 194 without ASD/developmental delay, and 121 with cancer (of whom 116 were in the no ASD/developmental delay group). Genome-wide evaluation of autosomal CNVs indicated an increased CNV burden, particularly duplications in genic regions, in patients with ASD/developmental delay compared with those without ASD/developmental delay (odds ratio [OR], 1.9; 95% CI, 1.1-3.4; P = .03) and those with cancer (OR, 2.5; 95% CI, 1.3-4.6; P = .003). Eleven of the 110 patients (10.0%) with ASD/developmental delay carried pathogenic and/or likely pathogenic CNVs associated with neurodevelopmental disorders, compared with 5 of 194 (2.6%) without ASD/developmental delay (OR, 4.2; 95% CI, 1.4-13.7; P = .008) and 2 of 121 (1.7%) with cancer (OR, 6.6; 95% CI, 1.6-44.5; P = .007). Evidence of an association between pathogenic and/or likely pathogenic CNVs and PHTS with ASD/developmental delay was further supported in a validation series of 69 patients with PHTS of genetically determined non-European ancestry.

CONCLUSIONS AND RELEVANCE

These findings suggest that copy number variations are associated with the ASD/developmental delay clinical phenotype in PHTS, providing proof of principle for similarly heterogeneous disorders lacking outcome-specific associations.

Pten haploinsufficiency disrupts scaling across brain areas during development in mice

Haploinsufficiency for PTEN is a cause of autism spectrum disorder and brain overgrowth; however, it is not known if PTEN mutations disrupt scaling across brain areas during development. To address this question, we used magnetic resonance imaging to analyze brains of male Pten haploinsufficient (Pten^+/-) mice and wild-type littermates during early postnatal development and adulthood. Adult Pten^+/- mice display a consistent pattern of abnormal scaling across brain areas, with white matter (WM) areas being particularly affected. This regional and WM enlargement recapitulates structural abnormalities found in individuals with PTEN haploinsufficiency and autism. Early postnatal Pten^+/- mice do not display the same pattern, instead exhibiting greater variability across mice and brain regions than controls. This suggests that Pten haploinsufficiency may desynchronize growth across brain regions during early development before stabilizing by maturity. Pten^+/- cortical cultures display increased proliferation of glial cell populations, indicating a potential substrate of WM enlargement, and provide a platform for testing candidate therapeutics. Pten haploinsufficiency dysregulates coordinated growth across brain regions during development. This results in abnormally scaled brain areas and associated behavioral deficits, potentially explaining the relationship between PTEN mutations and neurodevelopmental disorders.

PTEN Hamartoma tumor syndrome in childhood: A review of the clinical literature

PTEN hamartoma tumor syndrome (PHTS) is a highly variable autosomal dominant condition associated with intellectual disability, overgrowth, and tumor predisposition phenotypes, which often overlap. PHTS incorporates a number of historical clinical presentations including Bannayan-Riley-Ruvalcaba syndrome, Cowden syndrome, and a macrocephaly-autism/developmental delay syndrome. Many reviews in the literature focus on PHTS as an adult hamartoma and malignancy predisposition condition. Here, we review the current literature with a focus on pediatric presentations. The review starts with a summary of the main conditions encompassed within PHTS. We then discuss PHTS diagnostic criteria, and clinical features. We briefly address rarer PTEN associations, and the possible role of mTOR inhibitors in treatment. We acknowledge the limited understanding of the natural history of childhood-onset PHTS as a cancer predisposition syndrome and present a summary of important management considerations.

The Clinical Spectrum of PTEN Mutations

PTEN is a tumor suppressor gene that classically dampens the PI3K/AKT/mTOR growth-promoting signaling cascade. PTEN dysfunction causes dysregulation of this and other pathways, resulting in overgrowth. Cowden syndrome, a hereditary cancer predisposition and overgrowth disorder, was the first Mendelian condition associated with germline PTEN mutations. Since then, significant advances by the research and medical communities have elucidated how clinical phenotypic manifestations result from the underlying germline PTEN mutations. With time, it became evident that PTEN mutations can result in a broad phenotypic spectrum, causing seemingly disparate disorders from cancer to autism. Hence, the umbrella term of PTEN hamartoma tumor syndrome (PHTS) was coined. Timely diagnosis and understanding the natural history of PHTS are vital because early recognition enables gene-informed management, particularly as related to high-risk cancer surveillance and addressing the neurodevelopmental symptoms.

PTEN Hamartoma Tumor Syndrome: A Clinical Overview

The phosphatase and tensin homolog (PTEN) hamartoma tumor syndrome (PHTS) is a grouping of related genetic disorders that has been linked to germline mutations in the PTEN gene. These disorders include Cowden syndrome (CS), Bannayan–Riley–Ruvalcaba syndrome, adult Lhermitte–Duclos disease, and autism spectrum disorders associated with macrocephaly. The majority of the clinical information available on PHTS, however, is related to individuals diagnosed with CS. There is still much to be learned about this disorder, since diagnostic criteria for CS were only established in 1996, before the identification of the PTEN gene, and were based primarily on features seen in cases reported in the existing literature. More recently, however, data from several large series of patients have shown that a number of the clinical features associated with PTEN mutations are either more or less common than previously reported. In addition, we now know that only about 30–35% of patients meeting clinical diagnostic criteria for Cowden syndrome actually have a detectable PTEN mutation. Thus, our understanding of PTEN-related diseases and their management has evolved significantly over time. The United States National Comprehensive Cancer Network (NCCN) has produced and regularly updates practice guidelines which include clinical diagnostic criteria as well as guidelines for PTEN testing and management of patients with mutations. This review will summarize the overall literature on PHTS as well as recent findings which are broadening our understanding of this set of disorders.

Convergent microstructural brain changes across genetic models of autism spectrum disorder-A pilot study

Autism spectrum disorder (ASD) is a complex and genetically heterogeneous neuropsychiatric disease affecting as many as 1 in 68 children. Large scale genetic sequencing of individuals along the autism spectrum has uncovered several genetic risk factors for ASD; however, understanding how, and to what extent, individual genes contribute to the overall disease phenotype remains unclear. Neuroimaging studies of ASD have revealed a wide spectrum of structural and functional perturbations that are thought to reflect, in part, the complex genetic heterogeneity underpinning ASD. These perturbations, in both preclinical models and clinical patients, were identified in preclinical genetic models and ASD patients when compared to control populations; however, few studies have directly explored intrinsic differences between the models themselves. To better understand the degree and extent to which individual genes associated with ASD differ in their contribution to global measures of white matter microstructure, diffusion tensor imaging (DTI) was acquired from three novel rat genetic models of ASD (Fmr1, Nrxn1, and Pten) and DTI parameters of fractional anisotropy, mean, axial, and radial diffusivity were measured. Subsequent whole-brain voxel-wise analysis comparing each genetic model to each other (Fmr1:Nrxn1; Fmr1:Pten; Nrxn1:Pten) identified no significant differences in any comparison for all diffusion parameters assessed (FA, AD, MD, RD).

Variations in Mitochondrial Respiration Differ in IL-1ß/IL-10 Ratio Based Subgroups in Autism Spectrum Disorders

Autism spectrum disorder (ASD)⁷ is associated with multiple physiological abnormalities, including immune dysregulation, and mitochondrial dysfunction. However, an association between these two commonly reported abnormalities in ASD has not been studied in depth. This study assessed the association between previously identified alterations in cytokine profiles by ASD peripheral blood monocytes (PBMo) and mitochondrial dysfunction. In 112 ASD and 38 non-ASD subjects, cytokine production was assessed by culturing purified PBMo overnight with stimuli of innate immunity. Parameters of mitochondrial respiration including proton-leak respiration (PLR), ATP-linked respiration (ALR), maximal respiratory capacity (MRC), and reserve capacity (RC) were measured in peripheral blood mononuclear cells (PBMCs). The ASD samples were analyzed by subgrouping them into high, normal, and low IL-1ß/IL-10 ratio groups, which was previously shown to be associated with changes in behaviors and PBMo miRNA expression. MRC, RC, and RC/PLR, a marker of electron transport chain (ETC) efficiency, were higher in ASD PBMCs than controls. The expected positive associations between PLR and ALR were found in control non-ASD PBMCs, but not in ASD PBMCs. Higher MRC, RC, RC/PLR in ASD PBMCs were secondary to higher levels of these parameters in the high and normal IL-1ß/IL-10 ratio ASD subgroups than controls. Associations between mitochondrial parameters and monocyte cytokine profiles differed markedly across the IL-1ß/IL-10 ratio based ASD subgroups, rendering such associations less evident when ASD samples as a whole were compared to non-ASD controls. Our results indicate for the first time, an association between PBMC mitochondrial function and PBMo cytokine profiles in ASD subjects. This relationship differs across the IL-1ß/IL-10 ratio based ASD subgroups. Changes in mitochondrial function are likely due to adaptive changes or mitochondrial dysfunction, resulting from chronic oxidative stress. These results may indicate alteration in molecular pathways affecting both the immune system and mitochondrial function in some ASD subjects.

10q23.31 microduplication encompassing PTEN decreases mTOR signalling activity and is associated with autosomal dominant primary microcephaly

Background

Hereditary primary microcephaly (MCPH) is mainly characterised by decreased occipitofrontal circumference and variable degree of intellectual disability. MCPH with a dominant pattern of inheritance is a rare condition, so far causally linked to pathogenic variants in the ALFY, DPP6, KIF11 and DYRK1A genes.

Objective

This study aimed at identifying the causative variant of the autosomal dominant form of MCPH in a Brazilian family with three affected members.

Methods

Following clinical evaluation of two sibs and their mother presenting with autosomal dominant MCPH, array comparative genome hybridisation was performed using genomic DNA from peripheral blood of the family members. Gene and protein expression studies were carried out in cultured skin fibroblasts.

Results

A 382 kb microduplication at 10q23.31 was detected, encompassing the entire PTEN, KLLN and ATAD1 genes. PTEN haploinsufficiency has been causally associated with macrocephaly and autism spectrum disorder and, therefore, was considered the most likely candidate gene to be involved in this autosomal dominant form of MCPH. In the patients’ fibroblasts, PTEN mRNA and protein were found to be overexpressed, and the phosphorylation patterns of upstream and downstream components of the mammalian target of rapamycin (mTOR) signalling pathway were dysregulated.

Conclusions

Taken together, our results demonstrate that the identified submicroscopic 10q23.31 duplication in a family with MCPH leads to markedly increased expression of PTEN and reduced activity of the mTOR signalling pathway. These results suggest that the most probable pathomechanism underlying the microcephaly phenotype in this family involves downregulation of the mTOR pathway through overexpression of PTEN.