Search Results (26)

Background/Objectives: PTEN Hamartoma Tumour Syndrome (PHTS) is a rare inherited disorder caused by germline PTEN mutations, presenting with cancer predisposition and neurodevelopmental abnormalities, including macrocephaly. PTEN functions as a tumour suppressor by regulating the PI3K/AKT/mTOR pathway and contributes to cellular adhesion, migration, and genomic stability. As no curative therapy exists, gene therapy represents a promising avenue to correct the underlying genetic defect. Methods: In this study we evaluated the therapeutic potential of AAV9-mediated PTEN gene delivery in a Pten^Δ5/+ mouse model, which is predominantly characterized by progressive lymphoid hyperplasia leading to lymph node tumour development, as well as hepatic focal lesions and macrocephaly. Results: Systemic vector delivery did not improve lymph node enlargement which represents the predominant disease phenotype in the Pten^Δ5/+ mice at the doses tested, due to restricted vector biodistribution, but it did effectively rescue the hepatic lesions, including steatosis and steatohepatitis-like changes. Mechanistically, AAV-mediated PTEN expression significantly reduced elevated p-AKT levels, indicating attenuated hyperactivation of the PI3K/AKT/mTOR pathway. Additionally, intracranial delivery of the same vector in Pten^Δ5/+ mouse neonates ameliorated macrocephaly without apparent adverse effects. Conclusions: These findings highlight the therapeutic potential of AAV9-mediated PTEN gene therapy in PHTS, particularly for hepatic and neuroanatomical manifestations. Optimization of vector biodistribution and transduction efficiency will be critical for clinical translation. Full article

Pediatric gastrointestinal polyps are frequently associated with an underlying hereditary syndrome associated with multisystem manifestations and increased risk of early-onset cancer. Thus, the identification of polyps in a child should prompt evaluation with genetic testing to (1) characterize the syndrome to determine next clinical steps including surveillance recommendations, and (2) conduct cascade testing to identify affected family members. Given the considerations for pediatric genetic testing, including autonomy and psychosocial stressors associated with the early detection of a cancer risk syndrome, it is important to conduct targeted testing. Herein, we propose a stepwise approach to genetic testing in the pediatric patient with gastrointestinal polyps. Full article

Background and Clinical significance: Cowden syndrome is an autosomal dominant disorder caused by germline loss-of-function mutations in the PTEN tumor suppressor gene. It is characterized by multiple hamartomas and an increased lifetime risk of malignancies affecting the breast, thyroid, endometrium, and gastrointestinal (GI) tract. Pediatric presentations may include macrocephaly, scrotal tongue, and intellectual disability. Gastrointestinal involvement is frequent, with juvenile-like hamartomatous polyps occurring in at least half of patients and distributed throughout the GI tract, posing a risk for malignant transformation. Early diagnosis and surveillance are crucial for improving patient outcomes. Case Presentation: We report a case of a 10-year-old Caucasian female with Cowden syndrome, with a history of a malignant germ cell tumor of the ovary consisting of a yolk sac tumor and low-grade immature teratoma diagnosed at age six, and thyroidectomy at age nine. The patient has mild intellectual disability. Routine radiological surveillance revealed a right colon intraluminal mass, prompting referral for pediatric gastroenterology evaluation. Endoscopy identified multiple polyps throughout the colon, stomach, and small intestine. Polypectomy of larger lesions was performed, and histopathology confirmed juvenile-like hamartomatous polyps without dysplasia or malignancy. This case highlights the necessity of comprehensive gastrointestinal evaluation in pediatric Cowden syndrome patients. Endoscopic surveillance is essential for early detection and management of polyps. Conclusions: Given the multisystem involvement and elevated cancer risk associated with PTEN mutations, a multidisciplinary approach that includes genetic counseling, dermatologic evaluation, and ongoing oncologic monitoring is recommended. Increased awareness of gastrointestinal manifestations enables timely intervention and may reduce morbidity and mortality in this high-risk population. Full article

A 66-year-old female underwent a colonoscopy for persistent left lower abdominal discomfort and mucous stool passage. Endoscopic examination revealed a 3 mm sessile polyp in the ascending colon. Histopathological examination of the polyp showed preserved crypt architecture with a monomorphic spindle-cell proliferation within the lamina propria. Scattered ganglion cells were present and demonstrated immunoreactivity for Calretinin and S100. The lesion was diagnosed as a colonic ganglioneuroma. Ganglioneuromas are rarely localised to the gastrointestinal tract and often detected incidentally during colonoscopic screening. While solitary lesions are typically sporadic; diffuse or multiple ganglioneuromas may be associated with hereditary syndromes such as neurofibromatosis type 1, multiple endocrine neoplasia type 2B, and juvenile polyposis, the latter belonging to the PTEN-hamartoma tumour syndrome spectrum. Clinically, most colonic ganglioneuromas are asymptomatic, although some may present with nonspecific gastrointestinal symptoms. Despite their benign nature, rare cases of malignant transformation and association with adenocarcinoma have been reported. Full article

Background/Objectives: Twin and family studies suggest that 90% of the risk for autism spectrum disorder (ASD) is due to genetic factors, with 800 genes recognized as playing a role. An important gene is phosphatase and tensin homolog (PTEN), which plays a significant role in cancer as a tumor suppressor best known for causing overgrowth and PTEN hamartoma tumor syndromes (PHTS). Less well known are PTEN germline mutations with adverse neurodevelopmental impacts of macrocephaly, intellectual disability, and ASD, as well as other behavioral and psychiatric disturbances. There remains a limited understanding of whether these gene variants are associated with differing manifestations of PTEN-associated neurodevelopmental disorders. Methods: This review utilized comprehensive literature searches such as PubMed, OMIM, and Gene Reviews with keywords of PTEN, genetic factors, autism, and human studies and by searching genomic-protein functional networks with STRING computer-based programs for functional and genetic mechanisms. Results: This review explored the genetic underpinnings of PTEN gene variants causing altered interactive proteins and their mechanisms, biological processes, molecular functions, pathways, and disease–gene associations. We characterized specific gene–gene or protein–protein interactions and their functions relating to neurodevelopment, psychiatric disorders, and ASD that were found to be increased with PTEN gene variants. Conclusions: PTEN gene defects are among the most recognized genetic causes of ASD. PTEN gene variants and altered protein interactions and mechanisms described in our study are associated with an increased risk for tissue and organ overgrowth, macrocephaly, and distinct brain anomalies, specifically newly identified abnormal CSF dynamics. These genetic underpinnings and impacts on neurodevelopment are discussed. The genetic and protein findings identified may offer clues to effective treatment interventions, particularly when instituted at a young age, to improve long-term outcomes. Full article

Cutaneous manifestations can serve as early and sometimes the first clinical indicators in various hereditary cancer predisposition syndromes. This review provides a comprehensive overview of the dermatological signs associated with these syndromes, aiming to facilitate their recognition in clinical practice. Hereditary Breast and Ovarian Cancer syndrome is notably linked to an increased risk of melanoma. BAP1 tumor predisposition syndrome is characterized by BAP1-inactivated melanocytic tumors. Muir–Torre syndrome, a variant of Lynch syndrome, presents with distinctive cutaneous neoplasms such as sebaceous carcinomas, sebaceous adenomas, and keratoacanthomas. PTEN hamartoma tumor syndrome commonly features hamartomatous growths, trichilemmomas, acral keratoses, oral papillomas, and genital lentiginosis. Gorlin syndrome is marked by basal cell carcinomas and palmoplantar pits, while Peutz–Jeghers syndrome is identified by mucocutaneous pigmentation. In familial adenomatous polyposis, the cutaneous findings include epidermoid cysts, fibromas, desmoid tumors, and lipomas. Additionally, we examined monogenic disorders associated with cancer risk and skin involvement, such as xeroderma pigmentosum, neurofibromatosis type 1, familial atypical multiple-mole melanoma syndrome, and Fanconi anemia. The early recognition of these dermatologic features is essential for a timely diagnosis and the implementation of appropriate surveillance strategies in individuals with hereditary cancer syndromes. Full article

Background/Objectives: Cowden syndrome (or PTEN hamartoma tumor syndrome) (CS/PHTS) belongs to a group of inherited disorders associated with the development of multiple hamartomas. The clinical presentation of patients may include dysmorphic facial features, macrocephaly, developmental delay, and multiple benign and malignant tumors of various localizations. At the same time, only thyroid cancer is thought to have an increased risk in childhood. Skin lesions in CS/PHTS occur in 90–100% of patients and include multiple tricholemmoma, papilloma, acral keratosis, pigmentation changes, as well as rarer forms like vascular malformations, fibromas, neuromas, melanoma, and basal cell carcinoma. Methods: Next-generation sequencing and Sanger sequencing were used to search for PTEN genetic variants. A histological and immunohistochemical examination of tumor biopsies and skin lesions was performed. Results: A total of 13 patients from six families with CS/PHTS, including 10 children, were described. Seven pediatric patients belonged to families with paternal transmission of the PTEN pathogenic variants, while three others were de novo cases. Atypical manifestations in CS/PHTS were diffuse large B-cell lymphoma in one adult, a renal cell carcinoma, three germ cell tumors, and a linear epidermal nevus in pediatric patients. A literature review of the identified pathogenic variants in the PTEN gene was performed, assessing their clinical significance and analyzing the traditional and modified diagnostic criteria as applied to the pediatric population. Conclusions: Taking into account the low incidence of CS/PHTS, the data presented significantly expand our current understanding of this disease and guide physicians to consider a wider range of possible malignant neoplasms in pediatric patients with CS/PHTS. Full article

Distinct subgroups of rare brain tumors can be molecularly classified using whole genome DNA methylation profiling and next-generation sequencing. Furthermore, these tools can identify germline mutations contributing to carcinogenesis. Access to molecular testing in the clinical setting is vital for pathology laboratories to make an accurate diagnosis. One molecularly unique brain tumor requiring such tools is the papillary tumor of the pineal region (PTPR). Herein, we present a case report of a 21-year-old male presenting with macrocephaly and obstructive hydrocephalus due to the PTPR. Next-generation sequencing identified a pathogenic PTEN p.G132D mutation in the tumor and matched germline findings further identified PTEN Hamartoma Tumor Syndrome (PHTS). The case report tumor was initially misdiagnosed as ependymoma while methylation profiling classified it more specifically as a PTPR, Group B. To better understand the current status of PTPRs, we conducted a systematic review of recent cases reporting on the diagnostics, treatments, and outcomes for PTPR patients. To our knowledge, this is the first case report for PTPRs revealing an association with PHTS. Our review revealed inconsistencies in diagnostics, treatments, and outcomes for PTPR, and an underutilization of definitive molecular testing. Full article

(1) Background/Objectives: Women with PTEN hamartoma tumor syndrome (PHTS) face a significantly increased risk of breast cancer (up to 66%) and a high prevalence of benign breast lesions (30–75%), which can complicate cancer detection and underscore the need for effective surveillance strategies. This study aimed to evaluate the imaging characteristics of breast cancers and benign breast lesions using magnetic resonance imaging (MRI) and mammography, with the goal of improving early cancer detection, reducing unnecessary biopsies, and guiding future surveillance protocols. (2) Methods: This retrospective single-institution study included 65 PHTS women aged ≥18 years (2001–2021), 39 of whom participated in a high-risk breast cancer surveillance program. Imaging features of breast cancers from MRI and mammography (when available) and of benign breast lesions from MRI only were assessed independently by two breast radiologists and correlated with pathology reports. Sensitivity and performance of MRI and mammography in detecting breast cancers and benign breast lesions were analyzed using descriptive statistics and correlation analyses, with significance set at p < 0.05. (3) Results: Imaging was available for re-evaluation for 17 breast cancers (with MRI available for 10 cases and mammography for 15 cases) diagnosed in 11 women and 31 benign breast lesions (with MRI available for 29 cases and mammography for 26 cases) in 16 women. MRI identified 90% (9/10) of the breast cancers for which it was available as suspicious, with malignant features retrospectively identifiable in 50% of baseline scans. In comparison, mammography identified only 40% (6/15) of breast cancers and was notably less effective in women with dense breast tissue. For benign breast lesions, MRI identified all lesions (29/29), while mammography underperformed, correctly identifying only 58% (15/26). However, ambiguous enhancement features on MRI occasionally posed challenges in distinguishing between benign breast lesions and malignancies. (4) Conclusions: MRI significantly outperformed mammography in accurately characterizing both breast cancers and benign breast lesions in women with PHTS, particularly in younger women with dense breast tissue. These findings reinforce the critical role of MRI as the primary surveillance tool for this high-risk population, given that breast cancers in women with PHTS tend to exhibit typical malignant features on MRI. However, they also highlight the importance of careful interpretation of MRI findings for benign breast lesions and the need for additional strategies to minimize unnecessary interventions. Full article

Background: PTEN hamartoma tumor syndrome (PHTS) has evolved into an umbrella term for a range of syndromes, characterized by loss-of-function variants in the phosphatase and tensin homolog (PTEN) tumor suppressor gene on chromosome 10q23.31. This can result in a lifelong tumor predisposition in patients. Often, the syndrome is diagnosed in early childhood because of macrocephaly, dermatological findings, or development delay. Since the correlation between phenotype and genotype is weak, and the penetrance is age-dependent, this poses the question of the appropriate timing of potentially invasive and burdensome examinations for early cancer detection. Case: The present report describes an infant with cleft palate associated with PHTS, a rare occurrence, though the initial report of Cowden syndrome already pointed to oromaxillofacial abnormalities. The recent pediatric literature is reviewed to assess which clinical symptoms should raise suspicion of PHTS and may then lead to early genetic counseling. Conclusion: Since the amount of prospective data remains limited, and the estimation of tumor risk during infancy and adulthood is very difficult, we advocate for early and broad genetic testing in suspected cases, to gain more insights into this rare disease and allow for better counseling for patients and their families. Full article

The PTEN tumor suppressor is frequently targeted in tumors and patients with PTEN hamartoma tumor syndrome (PHTS) through nonsense mutations generating premature termination codons (PTC) that may cause the translation of truncated non-functional PTEN proteins. We have previously described a global analysis of the readthrough reconstitution of the protein translation and function of the human canonical PTEN isoform by aminoglycosides. Here, we report the efficient functional readthrough reconstitution of the PTEN translational isoform PTEN-L, which displays a minimal number of PTC in its specific N-terminal extension in association with disease. We illustrate the importance of the specific PTC and its nucleotide proximal sequence for optimal readthrough and show that the more frequent human PTEN PTC variants and their mouse PTEN PTC equivalents display similar patterns of readthrough efficiency. The heterogeneous readthrough response of the different PTEN PTC variants was independent of the length of the PTEN protein being reconstituted, and we found a correlation between the amount of PTEN protein being synthesized and the PTEN readthrough efficiency. Furthermore, combination of aminoglycosides and protein synthesis inducers increased the readthrough response of specific PTEN PTC. Our results provide insights with which to improve the functional reconstitution of human-disease-related PTC pathogenic variants from PTEN isoforms by increasing protein synthesis coupled to translational readthrough. Full article

PTEN Hamartoma Tumour Syndrome (PHTS) encompasses diverse clinical phenotypes, including Cowden syndrome (CS), Bannayan–Riley–Ruvalcaba syndrome (BRRS), Proteus syndrome (PS), and Proteus-like syndrome. This autosomal dominant genetic predisposition with high penetrance arises from heterozygous germline variants in the PTEN tumour suppressor gene, leading to dysregulation of the PI3K/AKT/mTOR signalling pathway, which promotes the overgrowth of multiple and heterogenous tissue types. Clinical presentations of CS range from benign and malignant disorders, affecting nearly every system within the human body. CS is the most diagnosed syndrome among the PHTS group, notwithstanding its weak incidence (1:200,000), for which it is considered rare, and its precise incidence remains unknown among other important factors. The literature is notably inconsistent in reporting the frequencies and occurrences of these disorders, adding an element of bias and uncertainty when looking back at the available research. In this review, we aimed to highlight the significant disparities found in various studies concerning CS and to review the clinical manifestations encountered in CS patients. Furthermore, we intended to emphasize the great significance of early diagnosis as patients will benefit from a longer lifespan while being unceasingly advised and supported by a multidisciplinary team. Full article

Females with PTEN Hamartoma Tumor Syndrome (PHTS) have breast cancer risks up to 76%. This study assessed associations between breast cancer and lifestyle in European female adult PHTS patients. Data were collected via patient questionnaires (July 2020–March 2023) and genetic diagnoses from medical files. Associations between lifestyle and breast cancer were calculated using logistic regression corrected for age. Index patients with breast cancer before PHTS diagnosis (breast cancer index) were excluded for ascertainment bias correction. In total, 125 patients were included who completed the questionnaire at a mean age of 44 years (SD = 13). This included 21 breast cancer indexes (17%) and 39 females who developed breast cancer at 43 years (SD = 9). Breast cancer patients performed about 1.1 times less often 0–1 times/week physical activity than ≥2 times (OR_total-adj = 0.9 (95%CI 0.3–2.6); consumed daily about 1.2–1.8 times more often ≥1 than 0–1 glasses of alcohol (OR_total-adj = 1.2 (95%CI 0.4–4.0); OR_{non-breastcancer-index-adj} = 1.8 (95%CI 0.4–6.9); were about 1.04–1.3 times more often smokers than non-smokers (OR_total-adj = 1.04 (95%CI 0.4–2.8); OR_{non-breastcancer-index-adj} = 1.3 (95%CI 0.4–4.2)); and overweight or obesity (72%) was about 1.02–1.3 times less common (OR_total-adj = 0.98 (95%CI 0.4–2.6); OR_{non-breastcancer-index-adj} = 0.8 (95%CI 0.3–2.7)). Similar associations between lifestyle and breast cancer are suggested for PHTS and the general population. Despite not being statistically significant, results are clinically relevant and suggest that awareness of the effects of lifestyle on patients’ breast cancer risk is important. Full article

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. Full article

Phosphatase and tensin homolog (PTEN) encodes a tumor-suppressive phosphatase with both lipid and protein phosphatase activity. The tumor-suppressive functions of PTEN are lost through a variety of mechanisms across a wide spectrum of human malignancies, including several rare cancers that affect pediatric and adult populations. Originally discovered and characterized as a negative regulator of the cytoplasmic, pro-oncogenic phosphoinositide-3-kinase (PI3K) pathway, PTEN is also localized to the nucleus where it can exert tumor-suppressive functions in a PI3K pathway-independent manner. Cancers can usurp the tumor-suppressive functions of PTEN to promote oncogenesis by disrupting homeostatic subcellular PTEN localization. The objective of this review is to describe the changes seen in PTEN subcellular localization during tumorigenesis, how PTEN enters the nucleus, and the spectrum of impacts and consequences arising from disrupted PTEN nuclear localization on tumor promotion. This review will highlight the immediate need in understanding not only the cytoplasmic but also the nuclear functions of PTEN to gain more complete insights into how important PTEN is in preventing human cancers. Full article