A retrospective chart review of the features of PTEN hamartoma tumour syndrome in children

Developmental and behavioral phenotypes of pediatric patients with PTEN hamartoma tumor syndrome

Our study characterized the neurodevelopmental spectrum of individuals with PTEN Hamartoma Tumor Syndrome (PHTS), a syndrome that predisposes to both neurodevelopmental phenotypes and cancer risk. We aim to better understand life-impacting neurodevelopmental features of PHTS. Our study recruited 20 children/adolescents with PHTS, who were then administered assessments for autism spectrum disorder (ASD) and other neurocognitive measures, including assessment of IQ, executive and adaptive functioning, and health-related quality of life. Thirteen individuals (65%) were identified as having ASD, of which five were newly diagnosed during the study. Of those, ASD symptom severity was in the mild-moderate range for 77%. Overall, IQ was in the average range, with a mean of 92.61 (SD 24.45, p = 0.5), though there was a non-statistically significant trend toward individuals without ASD having a higher mean IQ (102.7 vs 82.3; p = 0.1). Subjects had significant impairment in processing speed (mean 75.38, SD 24.75, p < 0.05), decreased adaptive functioning skills across all domains, and a trend toward having more executive functioning problems. Individuals with PHTS are at increased risk of neurodevelopmental disorders, including ASD and impaired executive and adaptive functioning. Although clear guidelines exist for cancer surveillance for individuals with PHTS, additional guidelines and screening for neurodevelopmental disorders are warranted.

Exploring the neurological features of individuals with germline PTEN variants: A multicenter study

OBJECTIVE

PTEN, a known tumor suppressor gene, is a mediator of neurodevelopment. Individuals with germline pathogenic variants in the PTEN gene, molecularly defined as PTEN hamartoma tumor syndrome (PHTS), experience a variety of neurological and neuropsychiatric challenges during childhood, including autism spectrum disorder (ASD). However, the frequency and nature of seizures and the utilization of allied health services have not been described.

METHODS

Young patients with PHTS and sibling controls were recruited across five centers in the United States and followed every 6-12 months for a mean of 2.1 years. In addition to the history obtained from caregivers, neurodevelopmental evaluations and structured dysmorphology examinations were conducted, and brain MRI findings, received therapies, and epilepsy characteristics were reported.

RESULTS

One hundred and seven patients with PHTS (median age 8.7 years; range 3-21 years) and 38 controls were enrolled. ASD and epilepsy were frequent among patients with PHTS (51% and 15%, respectively), with generalized epilepsy strongly associated with ASD. Patients with epilepsy often required two antiseizure medications. Neuroimaging revealed prominent perivascular spaces and decreased peritrigonal myelination in individuals with PHTS-ASD. Allied therapy use was frequent and involved physical, occupational, speech, and social skills therapies, with 89% of all patients with PHTS, regardless of ASD diagnosis, utilizing at least one service.

INTERPRETATION

This prospective, longitudinal study highlights the wide neurological spectrum seen in young individuals with PHTS. ASD is common in PHTS, comorbid with epilepsy, and allied health services are used universally. Our findings inform care discussions with families about neurological outcomes in PHTS.

The complexity of phosphatase and tensin homolog hamartoma tumor syndrome: A case report

Germline pathogenic variants found in the phosphatase and tensin homolog gene are associated with a range of rare syndromes that collectively fall under the umbrella of phosphatase and tensin homolog hamartoma tumor syndromes. Due to the wide array of possible clinical presentations and the varying degrees of symptom severity, many individuals with phosphatase and tensin homolog hamartoma tumor syndromes might remain undiagnosed for an extended period. We describe a case of a male child who received the diagnosis at the age of 12. His clinical features included macrocephaly, hypertrophy in the left arm, thyroid nodules, penile freckles, developmental delay, and an autism spectrum disorder. Whole exome sequencing revealed a de novo heterozygous variant in the phosphatase and tensin homolog. The case highlights the diverse and complex nature of phosphatase and tensin homolog hamartoma tumor syndromes, emphasizing the necessity for early diagnosis, multidisciplinary care, and surveillance protocols, offering the potential for improved prognostic outcomes and enhanced quality of life for affected individuals.

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.

Case report: Rare oral manifestations in Cowden syndrome with PTEN mutation

Background

Cowden syndrome (CS) is a rare genetic disorder associated with PTEN gene mutations. It is characterized by macrocephaly, specific mucocutaneous features, and a predisposition to benign and malignant tumors. Cases of CS primarily presenting with oral clinical manifestations are relatively uncommon.

Methods/Results

We report the case of a 41-year-old male proband who presented with bilateral commissural and lingual externally projecting symmetric lesions for over two years. The proband also exhibited other features, including macrocephaly, communication difficulties, and obesity. Similar oral clinical manifestations were observed in family members. Whole exome sequencing analysis revealed PTEN gene mutations associated with CS in both the proband and his younger brother. This case serves as a reminder to be aware of the diverse presentations of CS in oral clinical practice and highlights the importance of genetic testing for guiding diagnosis and treatment.

Conclusion

There are few reported cases of CS primarily presenting with oral lesions. This finding contributes to further understanding of certain aspects of the pathogenesis of CS and enhances awareness of CS cases primarily exhibiting oral clinical manifestations.

Genomic diversity in functionally relevant genes modifies neurodevelopmental versus neoplastic risks in individuals with germline PTEN variants

Individuals with germline PTEN variants (PHTS) have increased risks of the seemingly disparate phenotypes of cancer and neurodevelopmental disorders (NDD), including autism spectrum disorder (ASD). Etiology of the phenotypic variability remains elusive. Here, we hypothesized that decreased genomic diversity, manifested by increased homozygosity, may be one etiology. Comprehensive analyses of 376 PHTS patients of European ancestry revealed significant enrichment of homozygous common variants in genes involved in inflammatory processes in the PHTS-NDD group and in genes involved in differentiation and chromatin structure regulation in the PHTS-ASD group. Pathway analysis revealed pathways germane to NDD/ASD, including neuroinflammation and synaptogenesis. Collapsing analysis of the homozygous variants identified suggestive modifier NDD/ASD genes. In contrast, we found enrichment of homozygous ultra-rare variants in genes modulating cell death in the PHTS-cancer group. Finally, homozygosity burden as a predictor of ASD versus cancer outcomes in our validated prediction model for NDD/ASD performed favorably.

Clinical Guidelines for Diagnosis and Management of Cowden Syndrome/PTEN Hamartoma Tumor Syndrome in Children and Adults-Secondary Publication

Cowden syndrome (CS)/PTEN hamartoma tumor syndrome (PHTS) is a rare autosomal dominantly inherited condition caused by germline pathogenesis. It is associated with multiple hamartomatous lesions occurring in various organs and tissues, including the gastrointestinal tract, skin, mucous membranes, breast, thyroid, endometrium, and brain. Macrocephaly or multiple characteristic mucocutaneous lesions commonly develop in individuals in their 20s. This syndrome is occasionally diagnosed in childhood due to the occurrence of multiple gastrointestinal polyps, autism spectrum disorders, and intellectual disability. CS/PHTS can be diagnosed taking the opportunity of multigene panel testing in patients with cancer. Appropriate surveillance for early diagnosis of associated cancers is required because patients have a high risk of cancers including breast, thyroid, colorectal, endometrial, and renal cancers. Under these circumstances, there is growing concern regarding the management of CS/PHTS in Japan, but there are no available practice guidelines. To address this situation, the guideline committee, which included specialists from multiple academic societies, was organized by the Research Group on Rare and Intractable Diseases granted by the Ministry of Health, Labour, and Welfare, Japan. The present clinical guidelines explain the principles in the diagnosis and management of CS/PHTS, together with four clinical questions and the corresponding recommendations, incorporating the concept of the Grading of Recommendations Assessment, Development, and Evaluation system. Herein, we present an English version of the guideline, some of which have been updated, to promote seamless implementation of accurate diagnosis and appropriate management of pediatric, adolescent, and adult patients with CS/PHTS.

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.

SHH medulloblastoma and very early onset of bowel polyps in a child with PTEN hamartoma tumor syndrome

Phosphatase and tensin homolog (PTEN) hamartoma tumor syndrome (PHTS) is a cancer predisposition syndrome characterized by an increased risk of developing benign and malignant tumors, caused by germline pathogenic variants of the PTEN tumour suppressor gene. PTEN gene variants often present in childhood with macrocephaly, developmental delay, and/or autism spectrum disorder while tumors and intestinal polyps are commonly detected in adults. PHTS is rarely associated with childhood brain tumors with only two reported cases of medulloblastoma (MB). We report the exceptional case of an infant carrying a germline and somatic pathogenic variant of PTEN and a germline and somatic pathogenic variant of CHEK2 who developed a MB SHH in addition to intestinal polyposis.

Gastrointestinal Dysfunction in Genetically Defined Neurodevelopmental Disorders

Gastrointestinal symptoms are common in most forms of neurodevelopment disorders (NDDs) such as in autism spectrum disorders (ASD). The current patient-reported outcome measures with validated questionnaires used in the general population of children without NDDS cannot be used in the autistic individuals. We explore here the multifactorial pathophysiology of ASD and the role of genetics and the environment in this disease spectrum and focus instead on possible diagnostics that could provide future objective insight into the connection of the gut-brain-microbiome in this disease entity. We provide our own data from both humans and a zebrafish model of ASD called Phelan-McDermid Syndrome. We hope that this review highlights the gaps in our current knowledge on many of these profound NDDs and that it provides a future framework upon which clinicians and researchers can build and network with other interested multidisciplinary specialties.

Characterizing dermatologic findings among patients with PTEN hamartoma tumor syndrome: Results of a multicenter cohort study

BACKGROUND

Dermatologic phenotypes in PTEN hamartoma tumor syndrome (PHTS) are heterogeneous and poorly documented.

OBJECTIVE

To characterize dermatologic findings among PHTS and conduct an analysis of genotype-dermatologic phenotype associations.

METHODS

Mucocutaneous findings were reviewed in a multicenter cohort study of PHTS. Genotype-dermatologic phenotype associations were tested using multivariable regression.

RESULTS

A total of 201 patients were included. Children were significantly less likely than adults to have oral papillomas, vascular malformations, benign follicular neoplasms, and acral keratoses. There were no cases of skin cancer among children. Basal cell carcinoma, cutaneous squamous cell carcinoma, and melanoma developed in 5%, 2%, and 1% of White adults, respectively. After adjusting for age, missense mutations were associated with 60% lower odds of developing cutaneous papillomatous papules (odds ratio: 0.4; 95% confidence interval [0.2, 0.7]), oral papillomas (0.4; 95% confidence interval [0.2, 0.9]), and vascular malformations (0.4; 95% confidence interval [0.2, 0.8]).

LIMITATIONS

Partly retrospective data.

CONCLUSION

Children are less likely than adults to have certain dermatologic findings, likely due to age-related penetrance. The risk of pediatric melanoma and the lifetime risk of nonmelanoma skin cancer in PHTS may not be elevated. Missense variants may be associated with the development of fewer dermatologic findings but future validation is required.

The physical and psychiatric health conditions related to autism genetic scores, across genetic ancestries, sexes and age-groups in electronic health records

BACKGROUND

Although polygenic scores (PGS) for autism have been related to various psychiatric and medical conditions, most studies to date have been conducted in research ascertained populations. We aimed to identify the psychiatric and physical conditions associated with autism PGS in a health care setting.

METHODS

We computed PGS for 12,383 unrelated participants of African genetic ancestry (AF) and 65,363 unrelated participants of European genetic ancestry (EU) from Vanderbilt's de-identified biobank. Next, we performed phenome wide association studies of the autism PGS within these two genetic ancestries.

RESULTS

Seven associations surpassed the Bonferroni adjusted threshold for statistical significance (p = 0.05/1374 = 3.6 × 10-5) in the EU participants, including mood disorders (OR (95%CI) = 1.08(1.05 to 1.10), p = 1.0 × 10-10), autism (OR (95%CI) = 1.34(1.24 to 1.43), p = 1.2 × 10-9), and breast cancer (OR (95%CI) = 1.09(1.05 to 1.14), 2.6 × 10-5). There was no statistical evidence for PGS-phenotype associations in the AF participants. Conditioning on the diagnosis of autism or on median body mass index (BMI) did not impact the strength of the reported associations. Although we observed some sex differences in the pattern of associations, there was no significant interaction between sex and autism PGS. Finally, the associations between autism PGS and autism diagnosis were stronger in childhood and adolescence, while the associations with mood disorders and breast cancer were stronger in adulthood.

DISCUSSION

Our findings indicate that autism PGS is not only related to autism diagnosis but may also be related to adult-onset conditions, including mood disorders and some cancers.

CONCLUSIONS

Our study raises the hypothesis that genes associated with autism may also increase the risk for cancers later in life. Future studies are necessary to replicate and extend our findings.

Novel dermatological and skeletal features associated with PTEN variant in PTEN hamartoma tumor syndrome

PTEN hamartoma tumor syndromes (PHTS) comprise hamartomatous overgrowth syndromes associated with PTEN germline mutations. In this case report, we describe a variant identified by next generation sequencing causing peculiar dermatological and skeletal features not yet described in the literature. Being cognizant of such unique disease presentations in PHTS, that manifest at a very young age, could help facilitate a timely diagnosis by clinicians and thus the early education of families on active cancer surveillance. This specific case also strengthens the concept of variable presentation of PHTS and the need for genetic testing early on, even if not all criteria for PHTS are met for a formal clinical diagnosis.

Neuropathological signatures revealed by transcriptomic and proteomic analysis in Pten-deficient mouse models

PTEN hamartoma tumour syndrome is characterised by mutations in the human PTEN gene. We performed transcriptomic and proteomic analyses of neural tissues and primary cultures from heterozygous and homozygous Pten-knockout mice. The somatosensory cortex of heterozygous Pten-knockout mice was enriched in immune response and oligodendrocyte development Gene Ontology (GO) terms. Parallel proteomic analysis revealed differentially expressed proteins (DEPs) related to dendritic spine development, keratinisation and hamartoma signatures. However, primary astrocytes (ASTs) from heterozygous Pten-knockout mice were enriched in the extracellular matrix GO term, while primary cortical neurons (PCNs) were enriched in immediate-early genes. In ASTs from homozygous Pten-knockout mice, cilium-related activity was enriched, while PCNs exhibited downregulation of forebrain neuron generation and differentiation, implying an altered excitatory/inhibitory balance. By integrating DEPs with pre-filtered differentially expressed genes, we identified the enrichment of traits of intelligence, cognitive function and schizophrenia, while DEPs in ASTs were significantly associated with intelligence and depression.

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.

Thyroid findings in pediatric and adult patients with PTEN hamartoma tumor syndrome: A retrospective analysis, and literature review

PURPOSE

PTEN hamartoma tumor syndrome (PHTS) comprises a group of rare genetic conditions caused by germline mutations in PTEN gene and characterized by development of both benign and malignant lesions in many body tissues. In this study, we aimed to evaluate the incidence of thyroid findings in both adult and pediatric PHTS patients.

METHODS

A retrospectively analysis conducted in 19 (13 adult and 6 pediatric) patients with PHTS, all confirmed with genetic testing, observed from 2015 to 2021 at the Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico.

RESULTS

We found a thyroid involvement in 12 adult patients (92%): 11 patients had benign lesions (85%) and the remaining developed a follicular thyroid carcinoma (8.3%). The median age at time of the first available record was 30 years. Among benign lesions, multinodular goiter was the most observed finding (10/11, 91%). Only 1 out of 6 (16%) pediatric patients was diagnosed with a thyroid lesion (unifocal lesion in mild lymphocytic thyroiditis) at the age of 8 years.

CONCLUSIONS

Thyroid disorders affected nearly all adult PHTS patients, but a much lower proportion of pediatric patients. We discuss about the natural history of thyroid involvement, age of PHTS clinical onset, and optimized surveillance.

Strong Hereditary Predispositions to Colorectal Cancer

Cancer is one of the most common causes of death worldwide. A strong predisposition to cancer is generally only observed in colorectal cancer (5% of cases) and breast cancer (2% of cases). Colorectal cancer is the most common cancer with a strong genetic predisposition, but it includes dozens of various syndromes. This group includes familial adenomatous polyposis, attenuated familial adenomatous polyposis, MUTYH-associated polyposis, NTHL1-associated polyposis, Peutz-Jeghers syndrome, juvenile polyposis syndrome, Cowden syndrome, Lynch syndrome, and Muir-Torre syndrome. The common symptom of all these diseases is a very high risk of colorectal cancer, but depending on the condition, their course is different in terms of age and range of cancer occurrence. The rate of cancer development is determined by its conditioning genes, too. Hereditary predispositions to cancer of the intestine are a group of symptoms of heterogeneous diseases, and their proper diagnosis is crucial for the appropriate management of patients and their successful treatment. Mutations of specific genes cause strong colorectal cancer predispositions. Identifying mutations of predisposing genes will support proper diagnosis and application of appropriate screening programs to avoid malignant neoplasm.

Can the "female protective effect" liability threshold model explain sex differences in autism spectrum disorder?

Male sex is a strong risk factor for autism spectrum disorder (ASD). The leading theory for a "female protective effect" (FPE) envisions males and females have "differing thresholds" under a "liability threshold model" (DT-LTM). Specifically, this model posits that females require either a greater number or larger magnitude of risk factors (i.e., greater liability) to manifest ASD, which is supported by the finding that a greater proportion of females with ASD have highly penetrant genetic mutations. Herein, we derive testable hypotheses from the DT-LTM for ASD, investigating heritability, familial recurrence, correlation between ASD penetrance and sex ratio, population traits, clinical features, the stability of the sex ratio across diagnostic changes, and highlight other key prerequisites. Our findings reveal that several key predictions of the DT-LTM are not supported by current data, requiring us to establish a different conceptual framework for evaluating alternate models that explain sex differences in ASD.

Development and Progression of Thyroid Disease in PTEN Hamartoma Tumor Syndrome: Refined Surveillance Recommendations

Background: PTEN hamartoma tumor syndrome (PHTS) is associated with a high prevalence and early onset of differentiated thyroid cancer and benign thyroid disease. However, a consensus on the time of initiation and frequency of thyroid cancer surveillance has not yet been reached. Most commonly, guidelines recommend annual thyroid ultrasounds, but vary widely in the time of initiation, ranging from shortly after birth to 18 years of age. Minimal data are available on the development and progression of thyroid disease over time in this population. This study aimed to target this knowledge gap by investigating the time to develop thyroid nodules and thyroid cancer from an initial ultrasound in 76 PHTS patients. Methods: The electronic records of 281 prospectively accrued PHTS patients were retrospectively reviewed between 2005 and 2021, and 76 patients were identified as having at least two thyroid ultrasounds. Time-to-event analyses were performed, determining the probability of developing thyroid nodules and thyroid cancer over time. Results: We demonstrated that PHTS patients with an initial thyroid ultrasound without nodules (n = 41) had >90% likelihood of remaining free of a clinically actionable nodule at 3 years and an 85% likelihood at 6 years. None of these patients developed thyroid cancer over the entire follow-up period (mean 4.6 years). In patients with a clinically nonactionable nodule, defined as not meeting criteria for fine needle aspiration or thyroidectomy (n = 14), we demonstrated that 80% will not have an actionable nodule at 3 years, and none developed thyroid cancer over the entire follow-up period. Conclusions: Our observations suggest stratifying surveillance intervals based on thyroid ultrasound result, and support extending surveillance intervals in PHTS patients without nodules on ultrasound to 3-5 years, and patients with clinically nonactionable nodules to 2-3 years, in contrast to the current recommendation of annual ultrasounds. This change in practice would decrease the burden of frequent ultrasounds, especially in young children and adolescents who are more likely to have a normal or nonactionable ultrasound result.

Genomic characterization of lymphomas in patients with inborn errors of immunity

Inborn errors of immunity-associated lymphomas are characterized by distinct clinical features and genetic signatures.

Both germline and somatic alterations contribute to lymphomagenesis in patients with inborn errors of immunity.

Patients with inborn errors of immunity (IEI) have a higher risk of developing cancer, especially lymphoma. However, the molecular basis for IEI-related lymphoma is complex and remains elusive. Here, we perform an in-depth analysis of lymphoma genomes derived from 23 IEI patients. We identified and validated disease-causing or -associated germline mutations in 14 of 23 patients involving ATM, BACH2, BLM, CD70, G6PD, NBN, PIK3CD, PTEN, and TNFRSF13B. Furthermore, we profiled somatic mutations in the lymphoma genome and identified 8 genes that were mutated at a significantly higher level in IEI-associated diffuse large B-cell lymphomas (DLBCLs) than in non-IEI DLBCLs, such as BRCA2, NCOR1, KLF2, FAS, CCND3, and BRWD3. The latter, BRWD3, is furthermore preferentially mutated in tumors of a subgroup of activated phosphoinositide 3-kinase δ syndrome patients. We also identified 5 genomic mutational signatures, including 2 DNA repair deficiency-related signatures, in IEI-associated lymphomas and a strikingly high number of inter- and intrachromosomal structural variants in the tumor genome of a Bloom syndrome patient. In summary, our comprehensive genomic characterization of lymphomas derived from patients with rare genetic disorders expands our understanding of lymphomagenesis and provides new insights for targeted therapy.

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.

Gastrointestinal manifestations in PTEN hamartoma tumor syndrome

The PTEN hamartoma tumor syndrome (PHTS) is a heterogeneous set of multisystem disorders caused by germline pathogenic variants in the PTEN tumor suppressor gene. Manifestations include developmental anomalies and proliferative lesions. Evidence of involvement of the GI tract has accrued over time, leading to the incorporation of GI manifestations (multiple hamartomas, glycogenic acanthosis and colorectal cancer) into the diagnostic criteria. Polyps of the upper and lower GI tract are found in most adult patients and in a significant fraction of children. Polyps tend to be of mixed histology, with a predominance of hamartomas and ganglioneuromas. PHTS patients are also at increased risk of colorectal cancer, and surveillance by colonoscopy is advised starting at the age of 35-40 years. A number of additional manifestations, including eosinophilic gastrointestinal disorders, have been observed in few or single cases, and their association with PHTS has yet to be determined.

Striking a balance: PIP2 and PIP3 signaling in neuronal health and disease

Phosphoinositides are membrane phospholipids involved in a variety of cellular processes like growth, development, metabolism, and transport. This review focuses on the maintenance of cellular homeostasis of phosphatidylinositol 4,5-bisphosphate (PIP₂), and phosphatidylinositol 3,4,5-trisphosphate (PIP₃). The critical balance of these PIPs is crucial for regulation of neuronal form and function. The activity of PIP₂ and PIP₃ can be regulated through kinases, phosphatases, phospholipases and cholesterol microdomains. PIP₂ and PIP₃ carry out their functions either indirectly through their effectors activating integral signaling pathways, or through direct regulation of membrane channels, transporters, and cytoskeletal proteins. Any perturbations to the balance between PIP₂ and PIP₃ signaling result in neurodevelopmental and neurodegenerative disorders. This review will discuss the upstream modulators and downstream effectors of the PIP₂ and PIP₃ signaling, in the context of neuronal health and disease.

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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11689-021-09406-w.

Childhood Cancer Predisposition: An Overview for the General Pediatrician

Cancer predisposition syndromes (CPS), or genetic syndromes leading to increased cancer risk, are responsible for at least 10% of all childhood cancers. With advances in both tumor and germline sequencing, these syndromes have been uncovered both in patients with and without syndromic features and family history of cancer. Recognition of CPS in children and use of associated screening guidelines can improve morbidity and mortality from childhood cancer. Given the multidisciplinary approach needed for management of CPS, knowledge of clinical features and surveillance guidelines are essential for the general pediatrician. Pediatricians also play a vital role in anticipatory guidance regarding cancer prevention strategies and management of psychosocial stressors associated with ongoing screening. This article discusses 10 of the more common pediatric CPS, reasons to refer patients for CPS genetic testing and evaluation, and general cancer prevention strategies. [Pediatr Ann. 2022;51(1):e15-e21.].

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.

A scalable Drosophila assay for clinical interpretation of human PTEN variants in suppression of PI3K/AKT induced cellular proliferation

Gene variant discovery is becoming routine, but it remains difficult to usefully interpret the functional consequence or disease relevance of most variants. To fill this interpretation gap, experimental assays of variant function are becoming common place. Yet, it remains challenging to make these assays reproducible, scalable to high numbers of variants, and capable of assessing defined gene-disease mechanism for clinical interpretation aligned to the ClinGen Sequence Variant Interpretation (SVI) Working Group guidelines for 'well-established assays'. Drosophila melanogaster offers great potential as an assay platform, but was untested for high numbers of human variants adherent to these guidelines. Here, we wished to test the utility of Drosophila as a platform for scalable well-established assays. We took a genetic interaction approach to test the function of ~100 human PTEN variants in cancer-relevant suppression of PI3K/AKT signaling in cellular growth and proliferation. We validated the assay using biochemically characterized PTEN mutants as well as 23 total known pathogenic and benign PTEN variants, all of which the assay correctly assigned into predicted functional categories. Additionally, function calls for these variants correlated very well with our recent published data from a human cell line. Finally, using these pathogenic and benign variants to calibrate the assay, we could set readout thresholds for clinical interpretation of the pathogenicity of 70 other PTEN variants. Overall, we demonstrate that Drosophila offers a powerful assay platform for clinical variant interpretation, that can be used in conjunction with other well-established assays, to increase confidence in the accurate assessment of variant function and pathogenicity.

PTEN hamartoma tumour syndrome: what happens when there is no PTEN germline mutation?

Hereditary cancer syndromes represent ~10% of all incident cancers. It is important to identify individuals having these disorders because, unlike patients with sporadic cancer, these patients require specialised life-long care, with implications for their families. Importantly, the identification of alterations in cancer-predisposing genes facilitates gene-informed molecular diagnosis, cancer risk assessment and gene-specific clinical management. Moreover, knowledge about gene function in the inherited cancers offers insights towards biological processes pertinent to the more common sporadic cancers. Conversely, without a known gene, clinical management is less precise, and it is impossible to offer predictive testing of family members. PTEN hamartoma tumour syndrome (PHTS) is an umbrella term encompassing four overgrowth and cancer predisposition disorders associated with germline PTEN mutations. With time, it became evident that only a finite subset of individuals with PHTS-associated phenotypes harbour germline PTEN mutations. Therefore, non-PTEN aetiologies exist in PTEN wildtype patients. Indeed, gene discovery efforts over the last decade elucidated multiple candidate cancer predisposition genes. While a subset of genes (e.g. AKT1, PIK3CA) are biologically plausible as being key effectors within the PTEN signalling cascade, other genes required meticulous functional interrogation to explain their contribution to PHTS-related phenotypes. Collectively, the extensive phenotypic heterogeneity of the clinical syndromes typically united by PTEN is reflected by the genetic heterogeneity revealed through gene discovery. Validating these gene discoveries is critical because, while PTEN wildtype patients can be diagnosed clinically, they do not have the benefit of specific gene-informed risk assessment and subsequent management.

Toward better characterization of restricted and repetitive behaviors in individuals with germline heterozygous PTEN mutations

This study aimed to further our understanding of restricted and repetitive behaviors (RRB) among individuals with germline pathogenic mutations in PTEN by providing multimethod characterization and comparison of key RRB subdomains across individuals with PTEN mutations with autism spectrum disorder (ASD) (PTEN-ASD), with PTEN mutations without ASD (PTEN-No ASD) and with ASD and macrocephaly but without PTEN mutations (Macro-ASD). Of 86 total research participants, 38 had PTEN-ASD (M_age  = 8.93 years, SD_age  = 4.75), 25 Macro-ASD (M_age  = 11.99 years; SD_age  = 5.15), and 23 PTEN-No ASD (M_age  = 8.94 years; SD_age  = 4.85). The Repetitive Behavior Scale-Revised (RBS-R) and the Autism Diagnostic Interview-Revised (ADI-R) were used as measures of distinct RRB domains. There were significant group differences in the RBS-R repetitive motor behaviors (RMB; F = 4.52, p = 0.014, ω²  = 0.08), insistence on sameness (IS; F = 4.11, p = 0.02, ω²  = 0.05), and circumscribed interests (CI; F = 7.80, p = 0.001, ω²  = 0.14) scales. Post hoc comparisons showed that the PTEN-No ASD group had significantly lower RMB, IS, and CI scores compared to both PTEN-ASD and Macro-ASD groups. Importantly, PTEN-No ASD group still showed elevated RRB levels. Furthermore, there was a portion of individuals in PTEN-No ASD group whose Full-Scale Intelligence Quotient (FSIQ) was >70 that did not show floor level scores in the RMB domain. After adjusting for age and FSIQ scores, group differences were no longer statistically significant. RMB, IS, and CI domains showed distinct association patterns with sex, age, and FSIQ. This investigation provides the largest and most comprehensive characterization of distinct RRB domains in individuals with PTEN mutations to date. Despite the limitations, our findings have important assessment and treatment implications.

PTEN Hamartoma Syndrome in a Child Presenting With Malrotation, Panintestinal Polyps, Severe Anemia, and Protein-Losing Enteropathy

PTEN hamartoma syndrome (PTEN-HS) is a rare syndrome including neurologic, neurodevelopmental, integumentary, endocrine, and gastrointestinal manifestations. Eosinophilic disorders of the gastrointestinal system are diverse group of disorders reported to be more common in PTEN-HS. Our patient had malrotation and obstruction in infancy and subsequently developed macrocephaly and a lipoma. She presented at 4 years of age with both iron deficiency anemia and hypoalbuminemia from protein-losing enteropathy. She went on to endoscopy, colonoscopy, and video capsule endoscopy showing gastric, small intestinal, and colonic polyps but with histology including both a mixed histologic characterization of the polyps as expected with PTEN-HS, along with eosinophilic esophagitis, gastric, duodenal, colonic and polyp eosinophilia. She improved with enteral nutritional support and budesonide. Intestinal malrotation is a previously unrecognized feature of PTEN-HS, in our patient protein-losing enteropathy may have resulted from polyposis or eosinophilic gastrointestinal disorder. Albeit rare, PTEN-HS represents an elusive differential diagnosis with a broad spectrum including gastrointestinal symptomatology. Our case report illustrates the overlap of clinical, endoscopic, and histologic findings that can complicate PTEN-HS.

Dopaminergic Dysregulation in Syndromic Autism Spectrum Disorders: Insights From Genetic Mouse Models

Autism spectrum disorder (ASD) is a neurodevelopmental disorder defined by altered social interaction and communication, and repetitive, restricted, inflexible behaviors. Approximately 1.5-2% of the general population meet the diagnostic criteria for ASD and several brain regions including the cortex, amygdala, cerebellum and basal ganglia have been implicated in ASD pathophysiology. The midbrain dopamine system is an important modulator of cellular and synaptic function in multiple ASD-implicated brain regions via anatomically and functionally distinct dopaminergic projections. The dopamine hypothesis of ASD postulates that dysregulation of dopaminergic projection pathways could contribute to the behavioral manifestations of ASD, including altered reward value of social stimuli, changes in sensorimotor processing, and motor stereotypies. In this review, we examine the support for the idea that cell-autonomous changes in dopaminergic function are a core component of ASD pathophysiology. We discuss the human literature supporting the involvement of altered dopamine signaling in ASD including genetic, brain imaging and pharmacologic studies. We then focus on genetic mouse models of syndromic neurodevelopmental disorders in which single gene mutations lead to increased risk for ASD. We highlight studies that have directly examined dopamine neuron number, morphology, physiology, or output in these models. Overall, we find considerable support for the idea that the dopamine system may be dysregulated in syndromic ASDs; however, there does not appear to be a consistent signature and some models show increased dopaminergic function, while others have deficient dopamine signaling. We conclude that dopamine dysregulation is common in syndromic forms of ASD but that the specific changes may be unique to each genetic disorder and may not account for the full spectrum of ASD-related manifestations.

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.

[Genetic risk factors and their influence on neural development in autism spectrum disorders]

Genetic risk factors and their influence on neural development in autism spectrum disorders Abstract. Abstract. Autism spectrum disorders are etiologically based on genetic and specific gene x biologically relevant environmental risk factors. They are diagnosed based on behavioral characteristics, such as impaired social communication and stereotyped, repetitive behavior and sensory as well as special interests. The genetic background is heterogeneous, i. e., it comprises diverse genetic risk factors across the disorder and high interindividual differences of specific genetic risk factors. Nevertheless, risk factors converge regarding underlying biological mechanisms and shared pathways, which likely cause the autism-specific behavioral characteristics. The current selective literature review summarizes differential genetic risk factors and focuses particularly on mechanisms and pathways currently being discussed by international research. In conclusion, clinically relevant aspects and open translational research questions are presented.

The Skin in Cowden Syndrome

Cowden syndrome (CS) is an autosomal dominant condition caused by mutations in the phosphatase and tensin homolog (PTEN) gene, and is characterized by multiple hamartomas and a predisposition to malignant tumors. Characteristic skin lesions include trichilemmomas, acral keratosis, mucocutaneous neuromas, oral papillomas, and penile macules, and are often the first clues to the underlying diagnosis. Here, we discuss the mucocutaneous manifestations of CS, differential diagnoses of genetic causes of each cutaneous finding, genetic analyses for patients with skin manifestations, management of patients with CS, and potential new targeted therapies for CS.

The role of PTEN signaling in synaptic function: Implications in autism spectrum disorder

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) regulates several cellular processes including survival, proliferation, and metabolism. In the brain, PTEN is a key modulator of synaptic function, and is involved in regulating synaptogenesis, connectivity, and synaptic plasticity. Herein we discuss how alterations in PTEN can disturb these mechanisms, thus compromising normal synaptic function and consequently contributing to behavioral and cognitive phenotypes observed in autism spectrum disorder (ASD). As the role of PTEN in synaptic function is linked to ASD, a deeper understanding of this interaction will shed light on the pathological mechanisms involved in ASD, contributing to the development of new therapies.

Genetic heterogeneity of disorders with overgrowth and intellectual disability: Experience from a center in North India

Overgrowth, defined as height and/or OFC ≥ +2SD, characterizes a subset of patients with syndromic intellectual disability (ID). Many of the disorders with overgrowth and ID (OGID) are rare and the full phenotypic and genotypic spectra have not been unraveled. This study was undertaken to characterize the phenotypic and genotypic profile of patients with OGID. Patients with OGID were ascertained from the cohort of patients who underwent cytogenetic microarray (CMA) and/or exome sequencing (ES) at our center over a period of 6 years. Thirty-one subjects (six females) formed the study group with ages between 3.5 months and 13 years. CMA identified pathogenic deletions in two patients. In another 11 patients, a disease causing variant was detected by ES. The spectrum of disorders encompassed aberrations in genes involved in the two main pathways associated with OGID. These were genes involved in epigenetic regulation like NSD1, NFIX, FOXP1, and those in the PI3K-AKT pathway like PTEN, AKT3, TSC2, PPP2R5D. Five novel pathogenic variants were added by this study. NSD1-related Sotos syndrome was the most common disorder, seen in five patients. A causative variant was identified in 61.5% of patients who underwent only ES compared to the low yield of 11.1% in the CMA group. The molecular etiology could be confirmed in 13 subjects with OGID giving a diagnostic yield of 42%. The major burden was formed by autosomal dominant monogenic disorders. Hence, ES maybe a better first-tier genomic test rather than CMA in OGID.

The Clinical Spectrum of PTEN Hamartoma Tumor Syndrome: Exploring the Value of Thyroid Surveillance

INTRODUCTION

Phosphatase and tensin homolog (PTEN) hamartoma tumor syndrome (PHTS) comprises a collection of clinical features characterized by constitutional variants in PTEN. Several guidelines recommend thyroid screening, beginning at the pediatric age at the time of PHTS diagnosis; however, the benefits of early surveillance has not been well defined.

METHODS

We conducted a retrospective investigation of patients followed up at the Children's Hospital of Philadelphia with a diagnosis of PHTS between January 2003 and June 2019. In total, 81 patients younger than 19 years were identified.

RESULTS

The most common clinical feature at presentation was macrocephaly (85.1%), followed by impaired development (42.0%), skin/oral lesions (30.9%), and autism spectrum disorder (27.2%). A total of 58 of 81 patients underwent thyroid surveillance, with 30 patients (51.7%) found to have a nodule(s). Ultimately, 16 patients underwent thyroidectomy, with 7.4% (6/81) diagnosed with thyroid cancer. All thyroid cancer patients were older than 10 years at diagnosis, and all displayed low-invasive behavior. Of the patients younger than 10 years at the time of thyroid ultrasound (US) surveillance, 71.4% (15/21) had a normal US. The remaining 6 patients had thyroid nodules, including 4 undergoing thyroid surgery with benign histology.

DISCUSSION/CONCLUSION

Patients with macrocephaly, impaired cognitive development and thyroid nodules, and/or early-onset gastrointestinal polyps should undergo constitutional testing for PHTS. There does not appear to be a clinical advantage to initiating thyroid US surveillance before 10 years of age. In PHTS patients with a normal physical examination, thyroid US surveillance can be delayed until 10 years of age.

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.

Brief Report: Role of Parent-Reported Executive Functioning and Anxiety in Insistence on Sameness in Individuals with Germline PTEN Mutations

This study aimed to characterize the relationship between insistence on sameness (IS), executive functioning (EF) and anxiety among individuals with PTEN mutations and individuals with macrocephalic ASD. The sample included 38 individuals with PTEN mutation and ASD diagnosis (PTEN-ASD; M_age = 8.93 years, SD_age = 4.75), 23 with PTEN mutation without ASD (PTEN-no ASD; M_age = 8.94 years; SD_age = 4.85) and 25 with ASD and macrocephaly but with no PTEN mutation (Macro-ASD; M_age = 11.99 years; SD_age = 5.15). The final model accounted for 45.7% of variance in IS, with Set-Shifting EF subdomain as a unique independent predictor (t = 4.12, p < 0.001). This investigation provides the first preliminary evidence for the EF-anxiety-IS interrelationship in individuals with PTEN mutations and with macrocephalic ASD.

Cross-level analysis of molecular and neurobehavioral function in a prospective series of patients with germline heterozygous PTEN mutations with and without autism

Background

PTEN is a well-established risk gene for autism spectrum disorder (ASD). Yet, little is known about how PTEN mutations and associated molecular processes influence neurobehavioral function in mutation carriers with (PTEN-ASD) and without ASD (PTEN no-ASD). The primary aim of the present study was to examine group differences in peripheral blood-derived PTEN pathway protein levels between PTEN-ASD, PTEN no-ASD, and idiopathic macrocephalic ASD patients (macro-ASD). Secondarily, associations between protein levels and neurobehavioral functions were examined in the full cohort.

Methods

Patients were recruited at four tertiary medical centers. Peripheral blood-derived protein levels from canonical PTEN pathways (PI3K/AKT and MAPK/ERK) were analyzed using Western blot analyses blinded to genotype and ASD status. Neurobehavioral measures included standardized assessments of global cognitive ability and multiple neurobehavioral domains. Analysis of variance models examined group differences in demographic, neurobehavioral, and protein measures. Bivariate correlations, structural models, and statistical learning procedures estimated associations between molecular and neurobehavioral variables. To complement patient data, Western blots for downstream proteins were generated to evaluate canonical PTEN pathways in the PTEN-m3m4 mouse model.

Results

Participants included 61 patients (25 PTEN-ASD, 16 PTEN no-ASD, and 20 macro-ASD). Decreased PTEN and S6 were observed in both PTEN mutation groups. Reductions in MnSOD and increases in P-S6 were observed in ASD groups. Elevated neural P-AKT/AKT and P-S6/S6 from PTEN murine models parallel our patient observations. Patient PTEN and AKT levels were independently associated with global cognitive ability, and p27 expression was associated with frontal sub-cortical functions. As a group, molecular measures added significant predictive value to several neurobehavioral domains over and above PTEN mutation status.

Limitations

Sample sizes were small, precluding within-group analyses. Protein and neurobehavioral data were limited to a single evaluation. A small number of patients were excluded with invalid protein data, and cognitively impaired patients had missing data on some assessments.

Conclusions

Several canonical PTEN pathway molecules appear to influence the presence of ASD and modify neurobehavioral function in PTEN mutation patients. Protein assays of the PTEN pathway may be useful for predicting neurobehavioral outcomes in PTEN patients. Future longitudinal analyses are needed to replicate these findings and evaluate within-group relationships between protein and neurobehavioral measures.

Trial registration

ClinicalTrials.gov Identifier NCT02461446

Colorectal polyposis as a clue to the diagnosis of Cowden syndrome: Report of two cases and literature review

Cowden Syndrome (CS) is an autosomal dominant disorder characterized by hamartomatous growth in several organs and by an increased risk of malignancies, which makes its recognition essential to undertake risk reduction measures. Although the involvement of gastrointestinal tract is extremely common, awareness of this entity among gastroenterologists appears limited. We report on two unrelated patients: a 46-year-old male and a 38-year-old woman, who were referred to the Genetic Clinic because of the endoscopic finding of multiple colorectal polyps. Despite both displayed striking clinical (and, in the first case, familial) manifestations of Cowden Syndrome (PTEN Hamartoma Tumor Syndrome-PHTS), they had not been recognized before. Diagnosis of PHTS was confirmed by the detection of causative PTEN variants. Pathological examination of the polyps showed multiple histology types: hyperplastic, juvenile, serrated and lymphoid. Hyperplastic polyps analyzed from both patients failed to show BRAF V600E and KRAS codon 12/13 mutations, which provides evidence against their potential to evolve to colorectal cancer through the serrated pathway. We then reviewed the literature on gastrointestinal polyps detected in patients with Cowden Syndrome, in order to provide a comprehensive scenario of presentations: among a total of 568 patients reported in the literature, 91.7 % presented with colon polyps, with 63.0 % having two or more different histological types of polyps; besides, 58.5 % had extra-colonic polyps (located either in stomach and/or in small intestine). Finding multiple polyps with mixed and/or unusual histology should alert gastroenterologists and pathologists about the possible diagnosis of Cowden Syndrome and prompt the search for other manifestations of this condition in the patient.

Diagnostic Approach to Macrocephaly in Children

Macrocephaly affects up to 5% of the pediatric population and is defined as an abnormally large head with an occipitofrontal circumference (OFC) >2 standard deviations (SD) above the mean for a given age and sex. Taking into account that about 2-3% of the healthy population has an OFC between 2 and 3 SD, macrocephaly is considered as "clinically relevant" when OFC is above 3 SD. This implies the urgent need for a diagnostic workflow to use in the clinical setting to dissect the several causes of increased OFC, from the benign form of familial macrocephaly and the Benign enlargement of subarachnoid spaces (BESS) to many pathological conditions, including genetic disorders. Moreover, macrocephaly should be differentiated by megalencephaly (MEG), which refers exclusively to brain overgrowth, exceeding twice the SD (3SD-"clinically relevant" megalencephaly). While macrocephaly can be isolated and benign or may be the first indication of an underlying congenital, genetic, or acquired disorder, megalencephaly is most likely due to a genetic cause. Apart from the head size evaluation, a detailed family and personal history, neuroimaging, and a careful clinical evaluation are crucial to reach the correct diagnosis. In this review, we seek to underline the clinical aspects of macrocephaly and megalencephaly, emphasizing the main differential diagnosis with a major focus on common genetic disorders. We thus provide a clinico-radiological algorithm to guide pediatricians in the assessment of children with macrocephaly.

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.

Cutaneous lipomas and macrocephaly as early signs of PTEN hamartoma tumor syndrome

BACKGROUND

The diagnosis of PTEN hamartoma tumor syndrome (PHTS) is difficult in children because they usually do not meet diagnostic criteria. The objective of our study was to characterize lipoma as an early presentation of PHTS.

METHODS

We performed a retrospective review of children with PHTS diagnosed in French academic hospitals from 2000 to 2019. We included patients presenting at least one lipoma and PTEN-related disorder confirmed genetically.

RESULTS

Thirteen children were included (mean age 5.5 years [range 2.5-16]). All children had solitary (n = 5) or multiple (n = 8) lipomas, all located on the trunk. Clinical examination revealed macrocephaly in all patients. Genital lentiginosis was found in all patients in whom genitalia were examined (n = 6).

CONCLUSIONS

In addition to the classical presentation of PHTS with neurological disorders and macrocephaly, some patients, especially the youngest ones, have an initial dermatologic presentation with multiple lipomas. Search for penile freckling and macrocephaly in these patients allows for the diagnosis of PHTS. Lipomatosis should be a major diagnostic criterion in children.

Clinical genetic testing and counselling in autism spectrum disorder

Autism spectrum disorders (ASDs) are phenotypically as well as genetically heterogeneous developmental disorders with a strong heritability. Clinical and basic science research has described many replicated genetic risk factors. Many findings can well be translated into clinical human genetic practice. The current article summarizes results of genetic studies in ASD, provides a diagnostic algorithm for the clinical human genetic work-up reflecting the German health care system options and gives information with regard to the obligatory genetic counselling after a clinical genetic assessment.