Optical genome mapping identifies a novel pediatric embryonal tumor with a ZNF532::NUTM1 fusion.

The molecular characteristics of pediatric brain tumors have not only allowed for tumor subgrouping but have led to the introduction of novel treatment options for patients with specific tumor alterations. Therefore, an accurate histologic and molecular diagnosis is critical for optimized management of all pediatric patients with brain tumors, including central nervous system embryonal tumors. We present a case where optical genome mapping identified a ZNF532::NUTM1 fusion in a patient with a unique tumor best characterized histologically as a central nervous system embryonal tumor with rhabdoid features. Additional analyses including immunohistochemistry for NUT protein, methylation array, whole genome, and RNA-sequencing was done to confirm the presence of the fusion in the tumor. This is the first description of a pediatric patient with a ZNF532::NUTM1 fusion, yet the histology of this tumor is similar to that of adult cancers with ZNF::NUTM1 fusions reported in the literature. Although rare, the distinct pathology and underlying molecular characteristics of the ZNF532::NUTM1 tumor separates this from other embryonal tumors. Therefore, screening for this or similar NUTM1 rearrangements should be considered for all patients with unclassified central nervous system tumors with rhabdoid features to ensure accurate diagnosis. Ultimately, with additional cases, we may be able to better inform therapeutic management for these patients. © 2023 The Pathological Society of Great Britain and Ireland.

Case report: Tisagenlecleucel for treatment of relapsed B- acute lymphoblastic leukemia in a patient with CHEK2 mutation.

Background: Germline Checkpoint Kinase 2 gene (CHEK2) mutations can increase the risk of solid tumors. Recently, they have been identified as risk factors for hematologic malignancies. However, to the best of our knowledge, B-acute lymphoblastic leukemia (B-ALL) has never been described as a presenting manifestation of germline CHEK2 mutation. Chimeric antigen receptor-T (CAR-T) cell therapy directed against CD19 antigen (tisagenlecleucel) is a novel cellular therapy for treatment of relapsed/refractory (R/R) B-ALL. The use of tisagenlecleucel has not been described in patients with CHEK2 mutation. Case Presentation: We describe a case of a pediatric patient with a heterozygous pathogenic germline CHEK2 mutation (c.1100delC; p.Thr367Metfs*15) successfully treated with tisagenlecleucel for relapsed B-ALL to avoid hematopoietic cell transplant (HCT). The twelve-year-old boy was diagnosed with National Cancer Institute (NCI) high-risk B-ALL (white blood cell count >50,000/mcL), with no extramedullary disease. Cytogenetic analysis revealed normal karyotype but fluorescent in situ hybridization (FISH) showed 93% positivity for CRLF2::P2RY8 rearrangement. He was treated as per Children's Oncology Group (COG) AALL1131 therapy and achieved a complete remission. Seven months after diagnosis, he was found to have papillary thyroid carcinoma with no evidence of metastatic disease. The patient underwent a total thyroidectomy with central lymph node biopsy and radioactive iodine therapy. The patient's biological mother and fraternal twin brother carry the same germline CHEK2 mutation with no history of malignancy. The biological father tested negative for the familial mutation. The patient's genetic panel also identified three variants of unclear significance: CDKN2A (c.37 °C > T; p.Arg124Cys), FLCN (c.62G > A; p.Cys21Tyr) and SDHAF2 (c.139A > G; p.Met47Val). Extended family history also revealed a diagnosis of anaplastic thyroid cancer in maternal uncle at the age of 44 years. Fifteen months after diagnosis the patient had a relapse of B-ALL (both medullary and extramedullary with blasts in CSF), which was successfully treated with tisagenlecleucel. The patient remains in remission 3 years after receiving tisagenlecleucel. Conclusion: As conventional chemotherapy and radiation can potentially increase the risk of DNA damage and development of secondary malignancies, CD19 CAR-T therapy (tisagenlecleucel) can be used as a substitute for intensive re-induction chemotherapy and HCT in patients with a germline CHEK2 mutation.

Surveillance imaging and early surgical intervention for improved CNS tumor outcomes in children with Li-Fraumeni syndrome: Children's National Hospital experience and literature review.

OBJECTIVE: Li-Fraumeni syndrome (LFS) is a cancer predisposition syndrome caused by germline mutations in the TP53 gene. CNS tumors are the fourth most common tumor type in LFS, and recent screening guidelines demonstrate that early tumor detection is associated with improved long-term survival. However, there is a paucity of data regarding surgical intervention when lesions are identified in asymptomatic patients on surveillance imaging. The authors investigated this through their cohort and literature review. METHODS: The cohort consisted of children seen in the Pediatric Cancer Genetics Program at Children's National Hospital between August 2012 and August 2021. The authors also include a PubMed (MEDLINE) literature search of articles from 2006 to 2021 related to surveillance and CNS tumors in patients with LFS. Studies in which CNS tumors were not identified or detailed patient information was not provided were excluded. Patients from the selected articles and the authors' cohort were added for further analysis. RESULTS: Between August 2012 and August 2021, 10 children with LFS and CNS tumors were assessed at Children's National Hospital: 4 who were known carriers of the TP53 mutation had CNS lesions found on surveillance imaging, whereas 6 presented with symptomatic CNS lesions and were either known or subsequently found to have germline TP53 mutations. The literature search identified 148 articles, 7 of which were included in this review. Patients from the literature and the present cohort were added for a total of 56 CNS lesions. A majority of the low-grade CNS lesions (22/24, 92%) were found on surveillance protocols in asymptomatic patients, whereas the majority of the high-grade lesions (22/26, 85%) presented in symptomatic patients who were not undergoing routine surveillance or as the initial diagnosis of LFS. The authors noted a significant survival advantage in pediatric patients with low-grade lesions, with an overall survival of 100% at 30 months. Minor limitations of the study include patient sample size and limitations in the patient cohort due to this being a retrospective rather than a prospective study. CONCLUSIONS: Data presented in this study support surveillance protocols in LFS and demonstrate the importance of dedicated CNS imaging and early surgical intervention when lesions are identified. Systematic review registration no.: CRD42022372610 (www.crd.york.ac.uk/prospero).

Revisiting the Threshold for Cancer Genetics Referral in Patients With Wilms Tumor.

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in the Journal of Clinical Oncology, to patients seen in their own clinical practice.

Comfort with Pharmacogenetic Testing Amongst Pediatric Oncology Providers and Their Patients.

Background: Pharmacogenetic (PGx) testing, a component of personalized medicine, aims to ensure treatment efficacy while reducing side effects and symptoms. Before this testing becomes routine in the pediatric oncology population, nurses need to understand the knowledge and concerns of providers, patients, and family members with regard to the timing, extent, interpretation, and incorporation of PGx testing. Methods: As part of a comprehensive PGx study (larger study) for children diagnosed with cancer, we surveyed providers and caregivers of children with cancer about their knowledge of and comfort with PGx testing. Caregivers who declined to participate in the larger PGx study were also asked to participate in the survey. Chi-square tests and a two-sample t-test were used to compare variables. Results: One hundred and two participants from the larger PGx study and 12 families who refused (response rate of 77% and 54%, respectively) as well as 29 providers (88%) completed surveys. Families not on the study were less interested in and comfortable with PGx results. Both groups were concerned about health or life insurance discrimination and payment. Providers would like support in ordering PGx testing and interpreting PGx. Discussion: Providers remain wary of most PGx testing, uncomfortable with interpreting and applying the results. Families are interested in the possibilities of personalized prescribing while worried about who has access to their child's genetic information. Further education on relevant tests for providers, including nurses, and the testing process for families, including details on privacy and sharing of genetic information, appear necessary.

An integrated model of care utilizing community health workers to promote safe transitions of care.

BACKGROUND/OBJECTIVES: Healthcare systems' adoption and sustenance of successful transitional care models (TCMs) have been limited by cost-prohibitive resource needs. Cost-effective TCMs that improve patient outcomes are needed to promote adoption by healthcare systems and sustainability. This study evaluated the effectiveness of a TCM utilizing community health workers (CHWs) in reducing inappropriate healthcare utilization and costs. DESIGN: A cohort study with a pre-post intervention evaluation of the intervention group. SETTING: A 953-bed academic urban safety-net hospital. PARTICIPANTS: Eligible participants (N = 154) were hospitalized or had repeated emergency room (ER) visits, identified to be at high risk for readmission. INTERVENTION: Promotion of self-management skills acquisition and care coordination by CHWs achieved through predischarge interdisciplinary team meetings, regular home visits and phone contact, accompaniment to primary care physicians' (PCP) appointments, support with transportation, medications, and self-management education. MEASUREMENTS: Outcome measures were readmissions, ER visits, and PCP establishment. RESULTS: Mean age of participants was 67, 65% were male, 92% African American. There was a significant reduction in overall number of readmissions (Z = 9.6, p < 0.001), also observed at 30-day (Z = 5.5, p < 0.001), 3-month (Z = 4.3, p < 0.001), 6-month (Z = 4.0, p = 0.001), and 1-year (Z = 5.4, p < 0.001) post-intervention. There was a significant reduction in the overall number of ER visits (Z = 5.5, p < 0.001), also seen at 3-month (Z = 3.3, p < 0.001), 6-month (Z = 3.0, p < 0.001), and 1-year (Z = 4.0, p < 0.001) intervals. Care with a PCP was established in 86.6% of participants. Utilization costs were significantly lower post-intervention ($11,530,376.39 vs $4,017,493.17, p < 0.001). CONCLUSION: Use of CHWs during transitions of care may be a cost-effective approach to reducing healthcare utilization and costs and may promote adoption and sustainability within healthcare systems.

Atypical Presentations among Older Adults with COVID-19 Disease: A Need for Broadening the Differential Diagnosis.

Typical presenting symptoms of COVID-19 have been reported to be common in older adults. Current guidelines by the World Health Organization (WHO) and Centers for Disease Control (CDC) for testing and diagnosis are based on the presence of these typical symptoms. Several older adults seen at our hospital have presented atypically with symptoms such as delirium, falls, increasing the need for attention to diagnostic protocols since this has significant implications for early detection and patient outcomes, infection control and promotion of safety among healthcare providers. With the increased risk of fatality among older adults with COVID-19, appropriate diagnostic protocols are needed to ensure early diagnosis and management. Recognizing these atypical presentations in nursing homes would also facilitate early screening and cohorting in these congregate living facilities where older adults have had disproportionately high morbidity and mortality rates. We present two patients who presented with delirium and falls, found to have COVID-19 infection.

Cancer genetic counseling for childhood cancer predisposition is associated with improved levels of knowledge and high satisfaction in parents.

Previous surveys of adults with cancer have revealed increased levels of genetic knowledge, varying levels of worry, and high satisfaction with cancer genetic counseling. We sought to determine the impact of cancer genetic counseling on parental levels of genetic knowledge, worry about cancer, and satisfaction in the context of suspected cancer predisposition in a child. We hypothesized that parents would be satisfied with cancer genetic counseling and that cancer genetic counseling would improve baseline parental genetic knowledge and decrease levels of worry. Parents were recruited from a pediatric cancer predisposition clinic in the United States. A survey was administered to two cohorts: One cohort had received cancer genetic counseling in the past and only completed one survey (post-only, n = 26), and another cohort completed the survey before and after cancer genetic counseling (pre/post, n = 23). The survey included questions on demographics, knowledge of genetics, worry levels, and satisfaction with the cancer genetic counseling service. The post-genetic counseling survey also contained a free-text section for parents to indicate what they took away from the sessions. Parental levels of genetics knowledge increased by an average of 1.9 points (p = .01), with 65.2% of parents demonstrating an increase in genetics knowledge score. Average worry levels did not change significantly (p = .37), with 52.2% of parents indicating decreased worry, and 34.8% indicating increased worry. Overall, 91.8% of parents reported high levels of satisfaction. Our results show that cancer genetic counseling in a pediatric cancer predisposition clinic improves parental levels of genetics knowledge. Satisfaction rates suggest that parents find this service beneficial. These results demonstrate the positive impacts of cancer genetic counseling on parents of children in which a hereditary cancer syndrome is known or suspected.

A Pediatric Case of Transformed Mycosis Fungoides in a BRCA2 Positive Patient.

Cutaneous T-cell lymphomas are very rare in children. Although mycosis fungoides is the most common of these rare cutaneous T-cell lymphomas in children, transformation to an aggressive malignancy remains extremely uncommon, and there are no clear guidelines for clinical management in the pediatric population. In addition, the increased usage of next-generation sequencing for pediatric patients with unusual malignancies may result in the discovery of pathogenic germline mutations, though the association between these mutations and the patient's cancer is not always clear. We present here a unique pediatric case of transformed mycosis fungoides in a patient with BRCA2 mutation.

Somatic Mosaicism of IDH1 R132H Predisposes to Anaplastic Astrocytoma: A Case of Two Siblings.

Anaplastic astrocytomas are aggressive glial cancers that present poor prognosis and high recurrence. Heterozygous IDH1 R132H mutations are common in adolescent and young adult anaplastic astrocytomas. In a majority of cases, the IDH1 R132H mutation is unique to the tumor, although rare cases of anaplastic astrocytoma have been described in patients with mosaic IDH1 mutations (Ollier disease or Maffucci syndrome). Here, we present two siblings with IDH1 R132H mutant high grade astrocytomas diagnosed at 14 and 26 years of age. Analysis of IDHR132H mutations in the siblings' tumors and non-neoplastic tissues, including healthy regions of the brain, cheek cells, and primary teeth indicate mosaicism of IDHR132H. Whole exome sequencing of the tumor tissue did not reveal any other common mutations between the two siblings. This study demonstrates the first example of IDH1 R132H mosaicism, acquired during early development, that provides an alternative mechanism of cancer predisposition.

DICER1 and Associated Conditions: Identification of At-risk Individuals and Recommended Surveillance Strategies.

Pathogenic germline DICER1 variants cause a hereditary cancer predisposition syndrome with a variety of manifestations. In addition to conferring increased cancer risks for pleuropulmonary blastoma (PPB) and ovarian sex cord-stromal tumors, particularly Sertoli-Leydig cell tumor, individuals with pathogenic germline DICER1 variants may also develop lung cysts, cystic nephroma, renal sarcoma and Wilms tumor, nodular hyperplasia of the thyroid, nasal chondromesenchymal hamartoma, ciliary body medulloepithelioma, genitourinary embryonal rhabdomyosarcoma, and brain tumors including pineoblastoma and pituitary blastoma. In May 2016, the International PPB Registry convened the inaugural International DICER1 Symposium to develop consensus testing and surveillance and treatment recommendations. Attendees from North America, Europe, and Russia provided expert representation from the disciplines of pediatric oncology, endocrinology, genetics, genetic counseling, radiology, pediatric surgery, pathology, and clinical research. Recommendations are provided for genetic testing; prenatal management; and surveillance for DICER1-associated pulmonary, renal, gynecologic, thyroid, ophthalmologic, otolaryngologic, and central nervous system tumors and gastrointestinal polyps. Risk for most DICER1-associated neoplasms is highest in early childhood and decreases in adulthood. Individual and caregiver education and judicious imaging-based surveillance are the primary recommended approaches. These testing and surveillance recommendations reflect a consensus of expert opinion and current literature. As DICER1 research expands, guidelines for screening and treatment will continue to be updated. Clin Cancer Res; 24(10); 2251-61. ©2018 AACR.

DICER1-related Sertoli-Leydig cell tumor and gynandroblastoma: Clinical and genetic findings from the International Ovarian and Testicular Stromal Tumor Registry.

BACKGROUND: Ovarian sex cord-stromal tumors (OSCST) include juvenile granulosa cell tumors (JGCT), Sertoli-Leydig cell tumor (SLCT) and gynandroblastoma (GAB) among others. These ovarian sex cord-stromal tumors as well as other tumors including pleuropulmonary blastoma (PPB) may be associated with DICER1 mutations. We sought to describe the clinical and genetic findings from the first 107 individuals enrolled in the International Ovarian and Testicular Stromal Tumor Registry. METHODS: Medical and family history were obtained for individuals consecutively enrolled in the International Ovarian and Testicular Stromal Tumor Registry. Pathology was centrally reviewed. DICER1 sequencing was performed on blood and tumor tissue. RESULTS: Of the 107 participants, 49 had SLCT, 25 had JGCT and 5 had GAB. Nearly all (36/37) SLCTs and 4/4 GAB tested had a DICER1 mutation in an RNase IIIb domain hotspot; approximately half of these individuals had a predisposing germline DICER1 mutation. Metachronous SLCTs were seen in 3 individuals with germline DICER1 mutations. Other DICER1-associated conditions were seen in 19% of patients with SLCT or GAB. Three children of women with SLCT were diagnosed with PPB based on genetic testing and clinical screening during the course of this study. All were diagnosed with PPB in its earliest and most curable form (Type I), were treated with surgery alone, and are alive without evidence of disease. CONCLUSIONS: Recognition of the distinct genetic basis for a group of these tumors improves precise classification in difficult cases and promotes mutation-based screening and early detection.

A Comprehensive Review of Pediatric Tumors and Associated Cancer Predisposition Syndromes.

An understanding of the role of inherited cancer predisposition syndromes in pediatric tumor diagnoses continues to develop as more information is learned through the application of genomic technology. Identifying patients and their relatives at an increased risk for developing cancer is an important step in the care of this patient population. The purpose of this review is to highlight various tumor types that arise in the pediatric population and the cancer predisposition syndromes associated with those tumors. The review serves as a guide for recognizing genes and conditions to consider when a pediatric cancer referral presents to the genetics clinic.

Childhood Rhabdomyosarcoma in Association With a RASopathy Clinical Phenotype and Mosaic Germline SOS1 Duplication.

Childhood rhabdomyosarcoma (RMS) accounts for approximately 3.5% of cancer cases among children 0 to 14 years of age. Genetic conditions associated with high risk of childhood RMS include Li-Fraumeni syndrome, pleuropulmonary blastoma, Beckwith-Wiedemann syndrome, and some RASopathies, such as neurofibromatosis type 1, Costello syndrome (CS), and Noonan syndrome (NS). Here, we report the rare case of a 4-year-old girl with clinical features of NS who developed an embryonal RMS of the chest and needed emergent treatment. Molecular genetic testing identified a de novo, large, mosaic duplication of chromosome 2 encompassing the SOS1 gene, presumably caused by a mosaic, unbalanced translocation between chromosomes 2 and 17 found on routine cytogenetic analysis. Sequence analysis of all known genes causing Noonan spectrum disorders was negative. RMS has been reported in a few patients with NS, associated in very few with germline SOS1 mutations, but none with copy number abnormalities. This is the first report to our knowledge of early-onset RMS developing in a child with features of NS and a mosaic RAS pathway gene aberration, a large SOS1 duplication. We hypothesize that the inciting event for tumor development in this case is due to the germline mosaic duplication of SOS1, which was duplicated in all cells of the tumor, and the ultimate development of the tumor was further driven by multiple chromosomal aberrations in the tumor itself, all described as somatic events in isolated RMS tumors.

Temporal order of RNase IIIb and loss-of-function mutations during development determines phenotype in pleuropulmonary blastoma / DICER1 syndrome: a unique variant of the two-hit tumor suppression model.

Pleuropulmonary blastoma (PPB) is the most frequent pediatric lung tumor and often the first indication of a pleiotropic cancer predisposition,  DICER1 syndrome, comprising a range of other individually rare, benign and malignant tumors of childhood and early adulthood. The genetics of  DICER1-associated tumorigenesis are unusual in that tumors typically bear neomorphic missense mutations at one of five specific "hotspot" codons within the RNase IIIb domain of  DICER 1, combined with complete loss of function (LOF) in the other allele. We analyzed a cohort of 124 PPB children for predisposing  DICER1 mutations and sought correlations with clinical phenotypes. Over 70% have inherited or  de novo germline LOF mutations, most of which truncate the  DICER1 open reading frame. We identified a minority of patients who have no germline mutation, but are instead mosaic for predisposing  DICER1 mutations. Mosaicism for RNase IIIb domain hotspot mutations defines a special category of  DICER1 syndrome patients, clinically distinguished from those with germline or mosaic LOF mutations by earlier onsets and numerous discrete foci of neoplastic disease involving multiple syndromic organ sites. A final category of PBB patients lack predisposing germline or mosaic mutations and have sporadic (rather than syndromic) disease limited to a single PPB tumor bearing tumor-specific RNase IIIb and LOF mutations. We propose that acquisition of a neomorphic RNase IIIb domain mutation is the rate limiting event in  DICER1-associated  tumorigenesis, and that distinct clinical phenotypes associated with mutational categories reflect the temporal order in which LOF and RNase IIIb domain mutations are acquired during development.

A mosaic activating mutation in AKT1 associated with the Proteus syndrome.

BACKGROUND: The Proteus syndrome is characterized by the overgrowth of skin, connective tissue, brain, and other tissues. It has been hypothesized that the syndrome is caused by somatic mosaicism for a mutation that is lethal in the nonmosaic state. METHODS: We performed exome sequencing of DNA from biopsy samples obtained from patients with the Proteus syndrome and compared the resultant DNA sequences with those of unaffected tissues obtained from the same patients. We confirmed and extended an observed association, using a custom restriction-enzyme assay to analyze the DNA in 158 samples from 29 patients with the Proteus syndrome. We then assayed activation of the AKT protein in affected tissues, using phosphorylation-specific antibodies on Western blots. RESULTS: Of 29 patients with the Proteus syndrome, 26 had a somatic activating mutation (c.49G→A, p.Glu17Lys) in the oncogene AKT1, encoding the AKT1 kinase, an enzyme known to mediate processes such as cell proliferation and apoptosis. Tissues and cell lines from patients with the Proteus syndrome harbored admixtures of mutant alleles that ranged from 1% to approximately 50%. Mutant cell lines showed greater AKT phosphorylation than did control cell lines. A pair of single-cell clones that were established from the same starting culture and differed with respect to their mutation status had different levels of AKT phosphorylation. CONCLUSIONS: The Proteus syndrome is caused by a somatic activating mutation in AKT1, proving the hypothesis of somatic mosaicism and implicating activation of the PI3K-AKT pathway in the characteristic clinical findings of overgrowth and tumor susceptibility in this disorder. (Funded by the Intramural Research Program of the National Human Genome Research Institute.).

Molecular analysis expands the spectrum of phenotypes associated with GLI3 mutations.

A range of phenotypes including Greig cephalopolysyndactyly and Pallister-Hall syndromes (GCPS, PHS) are caused by pathogenic mutation of the GLI3 gene. To characterize the clinical variability of GLI3 mutations, we present a subset of a cohort of 174 probands referred for GLI3 analysis. Eighty-one probands with typical GCPS or PHS were previously reported, and we report the remaining 93 probands here. This includes 19 probands (12 mutations) who fulfilled clinical criteria for GCPS or PHS, 48 probands (16 mutations) with features of GCPS or PHS but who did not meet the clinical criteria (sub-GCPS and sub-PHS), 21 probands (6 mutations) with features of PHS or GCPS and oral-facial-digital syndrome, and 5 probands (1 mutation) with nonsyndromic polydactyly. These data support previously identified genotype-phenotype correlations and demonstrate a more variable degree of severity than previously recognized. The finding of GLI3 mutations in patients with features of oral-facial-digital syndrome supports the observation that GLI3 interacts with cilia. We conclude that the phenotypic spectrum of GLI3 mutations is broader than that encompassed by the clinical diagnostic criteria, but the genotype-phenotype correlation persists. Individuals with features of either GCPS or PHS should be screened for mutations in GLI3 even if they do not fulfill clinical criteria.

Hedgehog signaling regulates sensory cell formation and auditory function in mice and humans.

Auditory perception is mediated through a finite number of mechanosensory hair cells located in a specialized sensory epithelium within the inner ear. The formation of the appropriate number of hair cells and the location of those cells is crucial for normal auditory function. However, the factors that regulate the formation of this epithelium remain poorly understood. Truncating mutations in the transcription factor GLI3, a downstream effector of the Hedgehog (HH) pathway, lead to a partial loss of HH signaling and cause Pallister-Hall syndrome (PHS). Here, we report that cochleae from a mouse model of PHS (Gli3(Delta699)), which produces only the truncated, repressor form of GLI3, have a variably penetrant phenotype that includes an increase in the size of the sensory epithelium and the development of large ectopic sensory patches in Kölliker's organ (KO). Consistent with the mouse model, some PHS individuals exhibit hearing loss across a broad range of frequencies. Moreover, inhibition of HH signaling in vitro results in an increase in the size of the prosensory domain, a precursor population that gives rise to the sensory epithelium, whereas treatment with Sonic hedgehog (SHH) inhibits prosensory formation. Finally, we demonstrate that HH signaling within the cochlea regulates expression of prosensory markers and that the effects of HH in KO are dependent on activation of Notch, an inducer of prosensory fate. These results suggest that HH signaling plays a key role in the specification, size, and location of the prosensory domain, and therefore of hair cells, within the cochlea.

Newly delineated syndrome of congenital lipomatous overgrowth, vascular malformations, and epidermal nevi (CLOVE syndrome) in seven patients.

We present a series of seven patients who were previously diagnosed with Proteus syndrome, but who do not meet published diagnostic criteria for this disorder and whose natural history is distinct from that of Proteus syndrome. This newly recognized phenotype comprises progressive, complex, and mixed truncal vascular malformations, dysregulated adipose tissue, varying degrees of scoliosis, and enlarged bony structures without progressive bony overgrowth. We have named this condition congenital lipomatous overgrowth, vascular malformations, and epidermal nevi (CLOVE syndrome) on a heuristic basis. In contrast to the bony distortion so characteristic of Proteus syndrome, distortion in CLOVE syndrome occurs only following major or radical surgery. Here, we contrast differences and similarities of CLOVE syndrome to Proteus syndrome.