American Journal of Medical Genetics Part A

Medulloblastoma and other neoplasms in patients with heterozygous germline SUFU variants: A scoping review

AbstractIn 2002, heterozygous suppressor of fused variants (SUFU+/−) in the germline were described to have a tumor suppressor role in the development of pediatric medulloblastoma (MB). Other neoplasms associated with pathologic germline SUFU+/− variants have also been described among patients with basal cell nevus syndrome (BCNS; BCNS is also known as Gorlin syndrome, nevoid basal cell carcinoma [BCC] syndrome or Gorlin‐Goltz syndrome; OMIM 109400), an autosomal‐dominant cancer predisposition syndrome. The phenotype of patients with germline SUFU+/− variants is very poorly characterized due to a paucity of large studies with long‐term follow‐up. As such, there is a clinical need to better characterize the spectrum of neoplasms among patients with germline SUFU+/− variants so that clinicians can provide accurate counseling and optimize tumor surveillance strategies. The objective of this study is to perform a scoping review to map the evidence on the rate of medulloblastoma and to describe the spectrum of other neoplasms among patients with germline SUFU+/− variants. A review of all published literature in PubMed (MEDLINE), EMBASE, Cochrane, and Web of Science were searched from the beginning of each respective database until October 9, 2021. Studies of pediatric and adult patients with a confirmed germline SUFU+/− variant who were evaluated for the presence of any neoplasm (benign or malignant) were included. There were 176 patients (N = 30 studies) identified with a confirmed germline SUFU+/− variant who met inclusion criteria. Data were extracted from two cohort studies, two case‐control studies, 18 case series, and eight case reports. The median age at diagnosis of a germline SUFU+/− variant was 4.5 years where 44.4% identified as female and 13.4% of variants were de novo. There were 34 different neoplasms (benign and malignant) documented among patients with confirmed germline SUFU+/− variants, and the most common were medulloblastoma (N = 59 patients), BCC (N = 21 patients), and meningioma (N = 19 patients). The median age at medulloblastoma diagnosis was 1.42 years (range 0.083–3; interquartile range 1.2). When data were available for these three most frequent neoplasms (N = 95 patients), 31 patients (32.6%) had neither MB, BCC nor meningioma; 51 patients (53.7%) had one of medulloblastoma or BCC or meningioma; eight patients (8.4%) had two of medulloblastoma or BCC or meningioma, and five patients (5.3%) had medulloblastoma and BCC and meningioma. This is the first study to synthesize the data on the frequency and spectrum of neoplasms specifically among patients with a confirmed germline SUFU+/− variant. This scoping review is a necessary step forward in optimizing evidence‐based tumor surveillance strategies for medulloblastoma and estimating the risk of other neoplasms that could impact patient outcomes.

Update of the genotype and phenotype ofKMT2DandKDM6Aby genetic screening of 100 patients with clinically suspected Kabuki syndrome

AbstractKabuki syndrome is characterized by a variable degree of intellectual disability, characteristic facial features, and complications in various organs. Many variants have been identified in two causative genes, that is, lysine methyltransferase 2D (KMT2D) and lysine demethylase 6A (KDM6A). In this study, we present the results of genetic screening of 100 patients with a suspected diagnosis of Kabuki syndrome in our center from July 2010 to June 2018. We identified 76 variants (43 novel) inKMT2Dand 4 variants (3 novel) inKDM6Aas pathogenic or likely pathogenic. Rare variants included a deep splicing variant (c.14000‐8C>G) confirmed by RNA sequencing and an 18% mosaicism level for aKMT2Dmutation. We also characterized a case with a blended phenotype consisting of Kabuki syndrome, osteogenesis imperfecta, and 16p13.11 microdeletion. We summarized the clinical phenotypes of 44 patients including a patient who developed cervical cancer of unknown origin at 16 years of age. This study presents important details of patients with Kabuki syndrome including rare clinical cases and expands our genetic understanding of this syndrome, which will help clinicians and researchers better manage and understand patients with Kabuki syndrome they may encounter.

Natural history of Ollier disease and Maffucci syndrome: Patient survey and review of clinical literature

AbstractOllier disease (OD) and Maffucci syndrome (MS) are characterized by multiple enchondromas. Patients with MS also have benign vascular overgrowths that become malignant in 8.5% of cases. OD is characterized by multiple enchondromas, typically unilateral in distribution with a predilection for the appendicular skeleton. MS is characterized by multiple enchondromas bilaterally distributed in most of the cases. Both disorders feature multiple swellings on the extremity, deformity around the joints, limitations in joint mobility, scoliosis, bone shortening, leg‐length discrepancy, gait disturbances, pain, loss of function, and pathological fractures. About 50% of patients with OD or MS develop a malignancy, such as chondrosarcoma, glioma, and ovarian juvenile granulosa cell tumor. To better understand the natural history of OD and MS, we reviewed 287 papers describing patients with OD and MS. We also created a survey that was distributed directly to 162 patients through Facebook. Here, we compare the review of the cases described in the literature to the survey's responses. The review of the literature showed that: the patients with OD are diagnosed at a younger age; the prevalence of chondrosarcomas among patients with OD or MS was ~30%; in four patients, vascular anomalies were identified in internal organs only; and, the prevalence of cancer among patients with OD or MS was ~50%. With these data, health care providers will better understand the natural history, severity, and prognosis of these diseases and the prevalence of malignancies in these patients. Here, we recommend new guidelines for the care of patients with OD and MS.