Sotos syndrome with intestinal polyposis and pigmentary changes of the genitalia

We report two adult males with the Sotos syndrome, who also presented intestinal polyposis and pigmentary spotting of the shaft and glans penis. We propose that patients with the Sotos syndrome may develop hamartoneoplastic disease and we urge clinicians to consider this possibility in those patients.     

Adults with Sotos syndrome: review of 21 adults with molecularly confirmed NSD1 alterations, including a detailed case report of the oldest person

Sotos syndrome is a well‐described multiple anomaly syndrome characterized by overgrowth, distinctive craniofacial appearance, and variable learning disabilities. The diagnosis of Sotos syndrome relied solely on these clinical criteria until haploinsufficiency of the NSD1 gene was identified as causative. We describe a 63‐year‐old woman with classic features and a pathogenic NSD1 mutation, who we believe to be the oldest reported person with Sotos syndrome. She is notable for the diagnosis of Sotos syndrome late in life, mild cognitive limitation, and chronic kidney disease attributed to fibromuscular dysplasia for which she recently received a transplant. She has basal cell and squamous cell carcinoma for which her lifetime of sun exposure and fair cutaneous phototype are viewed as risk factors. We also reviewed previous literature reports (n = 11) for adults with Sotos syndrome, and studied patients ascertained in the Spanish Overgrowth Syndrome Registry (n = 15). Analysis was limited to 21/27 (78%) total patients who had molecular confirmation of Sotos syndrome (15 with a mutation, 6 with a microdeletion). With a mean age of 26 years, the most common features were learning disabilities (90%), scoliosis (52%), eye problems (43%), psychiatric issues (30%), and brain imaging anomalies (28%). Learning disabilities were more severe in patients with a microdeletion than in those with a point mutation. From this small study with heterogeneous ascertainment we suggest modest adjustments to the general healthcare monitoring of individuals with Sotos syndrome. Although this series includes neoplasia in four cases, this should not be interpreted as incidence. Age‐appropriate cancer surveillance should be maintained. © 2011 Wiley‐Liss, Inc.     

Hyperinsulinemic hypoglycemia of infancy in Sotos syndrome

Sotos syndrome (OMIM #117550) is a congenital syndrome characterized by overgrowth with advanced bone age, macrocephaly, and learning difficulties. Endocrine complications of this syndrome have not yet been fully described in previous reports. We here investigated the clinical manifestations of Sotos syndrome in Japanese patients who presented with hyperinsulinemic hypoglycemia of infancy. We recruited patients diagnosed as having Sotos syndrome who presented with the complication of hyperinsulinemia during the neonatal period using a survey of the abstracts of Pediatric Meetings in domestic areas of Japan from 2007 to 2011. As a result, five patients (four females and one male) were recruited to evaluate the clinical presentation of Sotos syndrome by reference to the clinical record of each patient. A 5q35 deletion including the NSD1 gene was detected in all patients. Major anomalies in the central nervous, cardiovascular, and genito‐urinary systems were frequently found. Hypoglycemia occurred between 0.5 and 3 hr after birth and high levels of insulin were initially found within 3 days of birth. The patients were treated with intravenous glucose infusion at a maximum rate of 4.6–11.0 mg/kg/min for 12–49 days. Three of the five patients required nasal tube feeding. One patient received medical treatment with diazoxide. This study shows that patients with Sotos syndrome may present with transient hyperinsulinemic hypoglycemia in the neonatal period. © 2012 Wiley Periodicals, Inc.     

Lymphoproliferative disorders in Sotos syndrome: Observation of two cases

Sotos syndrome is included among the overgrowth disorders, most of which have an increased risk of neoplasms. Sotos syndrome does not appear to be related to a specific tumor type, but rather to the development of solid tumors of ectodermal or mesodermal origin in general. We report on two Sotos syndrome patients who developed a non-Hodgkin lymphoma and an acute lymphoblastic leukaemia, respectively. Our experience suggests that there may exist a high frequency of lymphoproliferative disorders in Sotos syndrome, and points out the importance of a long-term follow-up of Sotos syndrome patients, to detect a possible neoplastic evolution. © 1996 Wiley-Liss, Inc.     

Marfanoid hypermobility caused by an 862 kb deletion of Xq22.3 in a patient with Sotos syndrome

Sotos syndrome is a rare genetic disorder characterized by overgrowth associated with macrocephaly and delayed psychomotor development. Patients with Sotos syndrome show 5q35 deletions involving NSD1 or its point mutations. We identified the common 5q35 deletion in a patient with atypical Sotos syndrome manifesting extremely severe developmental delay, joint hypermobility, and skin hyperextensibility, which are recognized as Marfanoid hypermobility syndrome. Further analyses were performed to identify the genetic cause of these additional findings. aCGH analysis revealed an additional 862 kb deletion of Xq22.3 in this patient, which was inherited from his healthy mother. The deleted region included five genes, including the nik‐related kinase gene (NRK), which would be a candidate gene for the patient's Marfanoid hypermobility, because it is a member of the glucokinase subfamily that are involved in activating the JNK pathway, and is expressed in developing skeletal musculature. Severe developmental delay seen in the patient may be derived from position effect of the deletion for neighboring interleukin 1 receptor accessory protein‐like 2 gene (IL1RAPL2), which is a candidate gene for X‐linked mental retardation. © 2011 Wiley‐Liss, Inc.     

Left ventricular noncompaction in Sotos syndrome

Sotos syndrome is an autosomal dominant condition characterized by pre- and postnatal overgrowth (tall stature and macrocephaly), a typical facial appearance, advanced bone age, and developmental delay. The syndrome is caused by mutations or deletions of the nuclear receptor binding SET domain protein 1 (NSD1) gene, which encodes a histone methyltransferase implicated in the regulation of chromatin. Left ventricular noncompaction (LVNC), also called left ventricular (LV) hypertrabeculation, is a rare disorder classified as a primary genetic cardiomyopathy by the American Heart Association. This condition is characterized by an altered myocardial wall due to arrest of embryonic compaction of the loose interwoven meshwork that makes up the fetal myocardial primordium. The cardiac manifestations of this cardiomyopathy are variable, ranging from an absence of symptoms to a progressive deterioration in cardiac function, with heart failure, arrhythmias, and systemic thromboemboli. We describe two unrelated patients who had LVNC, as based on echocardiographic findings, and Sotos syndrome, as based on physical features and molecular analysis. To our knowledge, the literature contains no previous reports of concomitant LVNC and Sotos syndrome. In the light of these two cases, we suggest that patients with Sotos syndrome be evaluated for LVNC cardiomyopathy when being screened for heart defects.     

Metacarpophalangeal pattern profile analysis in Sotos and Marfan syndrome

Patients with Sotos and Marfan syndrome have unusually long metacarpals and phalanges which may make the differential diagnosis difficult in younger children. Using Q-scores, we compared metacarpophalangeal pattern profile (MCPP) analysis in these two syndromes and identified distinct and different pattern profiles. This illustrates that the MCPPs are specific in these syndromes, even at an early age, and not related solely to the unusually long metacarpals and phalanges. For this study we used data from 50 Sotos patients (34 from the United Kingdom and 16 from the Netherlands, with a total of 95 hand films) and 36 Marfan patients (from the Netherlands, with 98 hand films). Of all patients over age 3 years the bone length (including the epiphysis) was determined. The patients under 7½ years (29 Sotos and 12 Marfan) were also measured without inclusion of the epiphysis. The patients measured without epiphysis had a relative short metacarpal 1 (MC1) and long distal phalanx 1 (DPh1) in Sotos syndrome, and a relative long MC1 and short DPh1 in Marfan syndrome. Between age 3 and 7½ years more than 90% of the films could be classified correctly using these two variables. Of the roentgenograms measured with epiphyses, about 80% were classified correctly. © 1994 Wiley-Liss, Inc.     

Hyperinsulinemic hypoglycemia in seven patients with de novo NSD1 mutations

Sotos syndrome is an overgrowth syndrome characterized by distinctive facial features and intellectual disability caused by haploinsufficiency of the NSD1 gene. Genotype–phenotype correlations have been observed, with major anomalies seen more frequently in patients with 5q35 deletions than those with point mutations in NSD1. Though endocrine features have rarely been described, transient hyperinsulinemic hypoglycemia (HI) of the neonatal period has been reported as an uncommon presentation of Sotos syndrome. Eight cases of 5q35 deletions and one patient with an intragenic NSD1 mutation with transient HI have been reported. Here, we describe seven individuals with HI caused by NSD1 gene mutations with three having persistent hyperinsulinemic hypoglycemia. These patients with persistent HI and Sotos syndrome caused by NSD1 mutations, further dispel the hypothesis that HI is due to the deletion of other genes in the deleted 5q35 region. These patients emphasize that NSD1 haploinsufficiency is sufficient to cause HI, and suggest that Sotos syndrome should be considered in patients presenting with neonatal HI. Lastly, these patients help extend the phenotypic spectrum of Sotos syndrome to include HI as a significant feature.     

Sotos syndrome and cutis laxa

Characteristics suggestive of connective tissue dysfunction have been described in Sotos syndrome and include joint hyperextensibility, pes planus, and a high arched palate. A variety of cutis laxa syndromes have also been described, some of them exhibiting mental retardation, but no reports have drawn an association with overgrowth or abnormal facies characteristic of Sotos syndrome. We report three patients with the anthropometric and dysmorphological appearance of classical Sotos syndrome in association with redundant skin folds, joint hypermobility, and, in two of the three, vesicoureteric reflux suggestive of a coexisting connective tissue disorder. All of the patients had a normal bone age suggesting that Sotos syndrome in its classically described form was not present and that this entity possibly reflects a related, perhaps allelic, condition.     

Sotos综合征的研究进展

Sotos综合征(MIM#117550)是一种以儿童期过度生长现象为特征的遗传病,主要表现为巨头畸形、特殊面容、骨龄提前以及不同程度的发育迟缓.目前已有数百名病例报道,具体发病率不详.约75%的病例是由NSD1基因内点突变或5q35微缺失所导致,欧裔患者多由5q35微缺失引起,而约50%日本患者主要由基因内点突变引起,仍有约25%病例未检测出NSDI基因异常,其具体致病机制尚不完全清楚.NSD1基因定位于染色体5q35,此基因编码一种组蛋白甲基化酶,该酶与转录调节过程有关.通过FISH(fluorescent in situ hybridization)分析、MLPA(multiplex ligation-dependent probe amplification)及实时定量荧光PCR反应等技术可以检测NSD1基因整体或部分缺失,直接测序可以检测出NSD1基因点突变.绝大部分NSD1基因异常为新生突变,多数为散发病例,但也发现数例家族性遗传病例.本病鉴别诊断主要为以生长过度为特征的疾病,包括Weaver综合征,Beckwith-Wiedeman综合征,脆性X染色体综合征等.目前本病尚无理想疗法,主要为对症治疗.出生后第一年内儿科随访对于本病临床并发症如脊柱侧弯及热性癫痫发作的治疗和预防监测有重要意义.     

A syndrome of short stature, microcephaly and speech delay is associated with duplications reciprocal to the common Sotos syndrome deletion

Genomic rearrangements are an increasingly recognized mechanism of human phenotypic variation and susceptibility to disease. Sotos syndrome is characterized by overgrowth, macrocephaly, developmental delay and advanced osseous maturation. Haploinsufficiency of NSD1, caused by inactivating point mutations or deletion copy number variants, is the only known cause of Sotos syndrome. A recurrent 2 Mb deletion has been described with variable frequency in different populations. In this study, we report two individuals of different ethnic and geographical backgrounds, with duplications reciprocal to the common Sotos syndrome deletion. Our findings provide evidence for the existence of a novel syndrome of short stature, microcephaly, delayed bone development, speech delay and mild or absent facial dysmorphism. The phenotype is remarkably opposite to that of Sotos syndrome, suggesting a role for NSD1 in the regulation of somatic growth in humans.     

Exclusion of growth factor gene mutations as a common cause of Sotos syndrome

Sotos syndrome is characterized by somatic overgrowth, i.e., macrocephaly and tall stature. Because the cause and pathogenesis of Sotos syndrome remain unknown, we selected nerve growth factor (NGF), brain‐derived neurotrophic factor (BDNF) and neurotrophin 3 (NT‐3) as possible genes mutated in Sotos syndrome. In seven patients with the classic phenotype, we excluded mutations in these growth factor genes. It is possible that these three genes are not involved in the cause of Sotos syndrome, or alternatively, mutations could not be identified in the small number of patients studied. © 2001 Wiley‐Liss, Inc.     

Heterogeneity of NSD1 alterations in 116 patients with Sotos syndrome

Sotos syndrome is an overgrowth syndrome characterized by distinctive facial features, learning difficulties, and macrocephaly with frequent pre- and postnatal overgrowth with advanced bone age. Here, we report on our experience in the molecular diagnostic of Sotos syndrome on 116 patients. Using direct sequencing and a quantitative multiplex PCR of short fluorescent fragments (QMPSF)-based assay allowing accurate detection of both total and partial NSD1 deletions, we identified NSD1 abnormalities in 104 patients corresponding to 102 Sotos families (90%). NSD1 point mutations were detected in 80% of the index cases, large deletions removing the NSD1 gene entirely in 14%, and intragenic NSD1 rearrangements in 6%. Among the 69 detected distinct point mutations, 48 were novel. The QMPSF assay detected an exonic duplication and a mosaic partial deletion. QMPSF mapping of the 15 large deletions revealed the heterogeneity of the deletions, which vary in size from 1 to 4.5 Mb. Clinical features of NSD1-positive Sotos patients revealed that the phenotype in patients with nontruncating mutations was less severe that in patients with truncating mutations. This study confirms the heterogeneity of NSD1 alterations in Sotos syndrome and therefore the need to complete sequencing analysis by screening for partial deletions and duplications to ensure an accurate molecular diagnosis of this syndrome.     

Reversed clinical phenotype due to a microduplication of Sotos syndrome region detected by array CGH: microcephaly, developmental delay and delayed bone age

Haploinsufficiency of the NSD1 gene due to 5q35 microdeletions or intragenic mutations is the major cause of Sotos syndrome characterized by generalized overgrowth, large hands and feet with advanced bone age, craniofacial dysmorphic features, learning disability, and possible susceptibility to tumors. Here, we report on a 14-month-old boy with a reverse phenotype of Sotos syndrome due to the reciprocal duplication of the 5q35.3 region, including the NSD1 gene, detected by array CGH. The phenotype includes delayed bone age, microcephaly, seizures, and failure to thrive. Our case suggests that the gene dosage effect of the NSD1 gene is the likely cause for the reversed phenotype of Sotos syndrome in this patient.     

Metacarpophalangeal pattern profile analysis in Sotos syndrome

The metacarpophalangeal pattern profile (MCPP) was analyzed on 16 Sotos syndrome patients. A mean Sotos syndrome profile was produced. Correlation studies confirm clinical homogeneity of Sotos syndrome individuals. Discriminant analysis of Sotos syndrome patients and normal individuals produces a function of two MCPP variables and age, which may provide a useful tool for diagnosis.     

Sotos syndrome and de novo balanced autosomal translocation (t(3;6)(p21;p21))

In this report we describe a 6-year-old boy with Sotos syndrome and a de novo apparently balanced 3/6 translocation (karyotype: 46,XY,t(3;6)(p21;p21)). Pre- and postnatal overgrowth are observed in an increasing number of conditions of variable etiology. In the Sotos syndrome autosomal dominant inheritance with variable expression has been documented. Here we discuss the importance of the cytogenetic findings and postulate a relationship between the invisible loss of chromosomal material at 3p21 and/or 6p21 and the expression of the autosomal dominant gene.     

Metacarpophalangeal pattern profile analysis in Sotos syndrome: a follow-up report on 34 subjects

Metacarpophalangeal pattern profile (MCPP) was determined on 34 Sotos syndrome individuals and compared with previous MCPP studies. The mean hand profile contained a major peak in the proximal phalangeal area and a smaller peak in the metacarpal area, while the distal hand bones were relatively short. There appear to be three recognized hand profiles in Sotos syndrome, which suggests heterogeneity of the syndrome, although correlation studies indicate clinical homogeneity of individuals in the younger age groups. Discriminant analysis of Sotos syndrome versus control subjects produced a function of two MCPP variables, plus age, which may be applied as another diagnostic tool.     

Sotos syndrome: antenatal presentation

There is little published information regarding the clinical presentation of Sotos syndrome in pregnancy. In this report, we describe the antenatal presentation of a child subsequently diagnosed with Sotos syndrome by molecular analysis. The pregnancy was complicated by a positive maternal serum screen and abnormal ultrasound findings including macrocephaly, polyhydramnios and decreased fetal movements. This is the first report of an elevated Down syndrome risk in a pregnancy with confirmed Sotos syndrome. Sotos syndrome should be included in the differential diagnosis of newborns with a normal karyotype where the pregnancy has demonstrated an increased risk for Down syndrome by maternal serum screening, especially in the presence of supportive ultrasound findings.     

Mutations in NSD1 are responsible for Sotos syndrome, but are not a frequent finding in other overgrowth phenotypes

Recently, deletions encompassing the nuclear receptor binding SET-Domain 1 (NSD1) gene have been described as the major cause of Japanese patients with the Sotos syndrome, whereas point mutations have been identified in the majority of European Sotos syndrome patients. In order to investigate a possible phenotype-genotype correlation and to further define the predictive value of NSD1 mutations, we performed mutational analysis of the NSD1 gene in 20 patients and one familial case with Sotos syndrome, five patients with Weaver syndrome, six patients with unclassified overgrowth/mental retardation, and six patients with macrocephaly/mental retardation. We were able to identify mutations within the NSD1 gene in 18 patients and the familial case with Sotos syndrome (90%). The mutations (six nonsense, eight frame shifts, three splice site, one missense, one in-frame deletion) are expected to result in an impairment of NSD1 function. The best correlation between clinical assessment and molecular results was obtained for the Sotos facial gestalt in conjunction with overgrowth, macrocephaly, and developmental delay. In contrast to the high mutation detection rate in Sotos syndrome, none of the patients with Weaver syndrome, unclassified overgrowth/mental retardation and macrocephaly/mental retardation, harbored NSD1 mutations. We tested for large deletions by FISH analysis but were not able to identify any deletion cases. The results indicate that the great majority of patients with Sotos syndrome are caused by mutations in NSD1. Deletions covering the NSD1 locus were not found in the patients analyzed here.