Marshall-Smith syndrome: Novel pathogenic variant and previously unreported associations with precocious puberty and aortic root dilatation

Marshall-Smith Syndrome (MRSHSS) is a very rare genetic disorder characterized by failure to thrive and characteristic dysmorphic features associated with accelerated osseous maturation. We present a nine-year-old girl who was diagnosed with MRSHSS based on characteristic clinical features supported by the identification of a novel de novo pathogenic variant in the NFIX gene. The patient also presented with precocious puberty diagnosed at five years of age and had an abnormal GnRH stimulation test indicative of central precocious puberty. Central precocious puberty has not been described in association with MRSHSS previously in the medical literature and broadens our knowledge of the natural history of MRSHSS. The causes of advanced bone age in this syndrome are also reviewed. Additionally, the patient showed progressive dilatation of the aortic root. Although connective tissue abnormalities have been described in association with MRSHSS, aortic root dilatation has not. Understanding the mechanism of comorbidities such as advanced bone age and aortic root dilatation in MRSHSS patients enables future development of anticipatory guidance, preventative care measures, and treatment guidelines.     

Marshall-Smith syndrome: the expanding phenotype.

We report a child of 3 years 9 months with the Marshall-Smith syndrome (MSS), characterised by the typical facial features, developmental delay, and advanced bone age. After the diagnosis was made at 5 months of age, careful observation for respiratory complications and failure to thrive was initiated. By 3 1/2 years of age, although our patient had no life threatening respiratory complications, investigation showed significant upper airway obstruction, which has been successfully treated. Aggressive treatment for failure to thrive has also allowed her to maintain a weight on the 50th centile. The purpose of this report is to suggest that early diagnosis and aggressive management may improve the ultimate prognosis with respect to the respiratory and feeding difficulties seen in this rare syndrome.     

Phenotype and natural history in Marshall-Smith syndrome

Marshall-Smith syndrome (MSS) is a distinctive entity of unknown etiology with fewer than 50 patients described in the medical literature to date. Through an International collaboration and use of an online wiki to facilitate data collection and sharing, we further delineate the phenotype and natural history of this syndrome. We present 15 new patients, the oldest being 30 years, provide an update on four previously published cases, and compare all patients with other patients reported in literature. Main clinical features are moderate to severe developmental delay with absent or limited speech, unusual behavior, dysharmonic bone maturation, respiratory compromise secondary to upper airway obstruction, short stature, and kyphoscoliosis. Facial features are characteristic with high forehead, underdeveloped midface, proptosis, anteverted nares, and everted lips. Minor abnormalities of brain morphology such as hypoplasia of the corpus callosum are common. Mortality from respiratory complications is high, but airway support increasingly allows survival into adulthood. Array-CGH was performed on 12 of the cohort and no copy number variants of clear clinical relevance were identified. The present study is the first reported use of an online wiki to aid delineation of a genetic syndrome, and illustrates its value in collecting detailed data in rare conditions.     

Osseous fragility in Marshall-Smith syndrome

Marshall-Smith syndrome is characterized by accelerated osseous maturation, craniofacial anomalies, failure to thrive, psychomotor delay, hypotonia, pulmonary dysfunction, and limited life expectancy. We describe a 7-year-old girl who, in addition to meeting these criteria for Marshall-Smith syndrome, had multiple fractures and skeletal anomalies. The purpose of this report is to draw attention to Marshall-Smith syndrome as one of the skeletal dysplasias characterized by osseous fragility.     

Marshall-Smith syndrome: natural history and evidence of an osteochondrodysplasia with connective tissue abnormalities

The Marshall-Smith syndrome (MSS) is a distinct malformation syndrome characterized by accelerated skeletal maturation, relative failure to thrive, respiratory difficulties, mental retardation, and unusual facies, including prominent forehead, shallow orbits, blue sclerae, depressed nasal bridge, and micrognathia. At least 33 cases have been reported in the literature, mostly as single case reports or small series. The purpose of the present study is to report on the clinical findings and natural history of MSS in five children and to review the features of three others previously reported, with particular attention to the skeletal and connective tissue findings. Our study demonstrates an increased rate of nontraumatic fractures and other bony and connective tissue abnormalities that support the hypothesis that MSS should be considered an osteochondrodysplasia. In addition, long-term survival beyond infancy is possible if respiratory problems are expectantly and aggressively managed.     

Sib pair with previously unreported skeletal dysplasia

We report on a consanguineous Lebanese family in which a sister and brother had developmental delay, dysmorphic facial appearance, narrow chest, prominent abdomen, and short limbs. Neonatal radiographs disclosed a bell-shaped thorax, short ribs, some with a cupped end, severe platyspondyly, square iliac bones, horizontal acetabula with medial and lateral spurs, hypoplastic ischia, short long bones, slight widening of the distal femoral metaphyses, and absence of epiphyseal ossification of the knees. The girl died at age 9 months as a result of respiratory insufficiency. A clinical and radiological follow-up of the boy showed that the axial hypotonia, minor anomalies, and short stature were still present, whereas the bone abnormalities had improved. Differential diagnosis suggests that this is a new type of chondrodysplasia.     

Frontonasal malformation and cloacal exstrophy: A previously unreported association

We report on a child with frontonasal malformation (FNM) and cloacal exstrophy, a combination of findings that have not been reported previously. In FNM and cloacal exstrophy, associated malformations are rare. FNM and cloacal exstrophy both represent abnormalities of the development of the midline field; this combination of anomalies in this patient suggests an impairment of caudal and cranial midline development during blastogenesis. © 1995 Wiley-Liss, Inc.     

Complete overlap of PHACE syndrome and sternal malformation--vascular dysplasia association

PHACE syndrome is the term applied to the association of posterior fossa brain abnormalities, hemangiomas, arterial anomalies in the cranial vasculature, coarctation of the aorta/cardiac defects, and eye abnormalities. An overlap with the sternal malformation/vascular dysplasia association has been described. We report an adult patient with complete manifestations of both conditions. As an adult she has demonstrated resolution of the hemangiomas and only mild intellectual difficulties.     

Heterozygous HESX1 mutations associated with isolated congenital pituitary hypoplasia and septo-optic dysplasia

We have previously shown that familial septo-optic dysplasia (SOD), a syndromic form of congenital hypopituitarism involving optic nerve hypoplasia and agenesis of midline brain structures, is associated with homozygosity for an inactivating mutation in the homeobox gene HESX1/Hesx1 in man and mouse. However, as most SOD/congenital hypopituitarism occurs sporadically, the possible contribution of HESX1 mutations to the aetiology of these cases is presently unclear. Interestingly, a small proportion of mice heterozygous for the Hesx1 null allele show a milder SOD phenocopy, implying that heterozygous mutations in human HESX1 could underlie some cases of congenital pituitary hypoplasia with or without midline defects. Accordingly, we have now scanned for HESX1 mutations in 228 patients with a broad spectrum of congenital pituitary defects, ranging in severity from isolated growth hormone deficiency to SOD with panhypopituitarism. Three different heterozygous missense mutations were detected in individuals with relatively mild pituitary hypoplasia or SOD, which display incomplete penetrance and variable phenotype amongst heterozygous family members. Gel shift analysis of the HESX1-S170L mutant protein, which is encoded by the C509T mutated allele, indicated that a significant reduction in relative DNA binding activity results from this mutation. Segregation analysis of a haplotype spanning 6.1 cM, which contains the HESX1 locus, indicated that only one HESX1 mutation was present in the families containing the C509T and A541G mutations. These results demonstrate that some sporadic cases of the more common mild forms of pituitary hypoplasia have a genetic basis, resulting from heterozygous mutation of the HESX1 gene.     

Rosai-Dorfman Disease: A previously unreported association with Sickle Cell Disease

Background  

Rosai-Dorfman Disease is an uncommon benign systemic histio-proliferative disease. This is the first time the disease, although more common in people of African descent, is described in association with Sickle cell disease.     

VATER association: report of a case with three unreported malformations.

The VATER association is the sporadic non-random association of Vertebral anomalies, Anal atresia, Tracheo-oesophageal fistula with Esophageal atresia, Renal defects, and Radial limb dysplasia. Cardiac defects are common, as are other limb malformations. The present report describes a premature infant with most of the known major and minor defects of the association as well as agenesis of the bladder and penis and an askeletal rudimentary tail. The latter have not previously been described.     

Case of partial trisomy 2q3 with clinical manifestations of Marshall-Smith syndrome

We describe a girl with physical anomalies, accelerated skeletal maturation, failure to thrive, and respiratory difficulties consistent with a diagnosis of Marshall-Smith syndrome (MSS). Chromosome analysis showed an inverted duplication of chromosome 2 [46,XX,inv dup(2)(q37q32) de novo] identified by G banding and confirmed by FISH. Several cases of trisomy 2q3 have been reported and established a syndrome, but the present case is the first to be associated with accelerated skeletal maturation and a clinical picture resembling MSS. This raises the possibility that the cause of MSS involves the q3 region of chromosome 2. Few reports of MSS include study of the karyotype, although the chromosomes were apparently normal in those cases where they have been examined. We suggest that karyotyping be undertaken with particular attention to the 2q3 region in patients with suspected MSS. It also would be prudent to assess bone age in all children with trisomy 2q. Am. J. Med. Genet. 85:185–188, 1999. © 1999 Wiley-Liss, Inc.     

A pigmentary skin defect is a new finding in Marshall-Smith syndrome

Marshall–Smith Syndrome (OMIM 602535) was described initially by Marshall in two infants with a syndrome characterized by accelerated skeletal maturation, failure to thrive, and dysmorphic facial features. We report a new patient with clinical features of Marshall–Smith syndrome with additional findings such as hyperpigmented lines on trunk and the four extremities. © 2011 Wiley‐Liss, Inc.     

Pallister-Hall syndrome: unreported skeletal features of a GLI3 mutation

We describe two patients with Pallister-Hall syndrome (PHS), both with evidence of a generalized skeletal dysplasia as typified by upper and lower acromesomelic limb shortening and the previously unreported fibular hypoplasia, radio-ulnar bowing, and proximal epiphyseal hypoplasia. Genomic DNA was only available for sequencing analysis in patient 2 and the mutation, c.3386_3387delTT was detected in exon 14 of the GL13 gene. It is also possible that the findings in patient 1 represent the phenotypic expression of a novel GLI3 mutation. This report further expands the PHS phenotype and raises the possibility of specific GLI3 mutations resulting in more severe skeletal features. It also suggests that PHS should be included in the differential diagnosis of antenatally ascertained acromesomelic limb shortening and bowing with fibular hypoplasia particularly in the presence of polysyndactyly.     

Renal-hepatic-pancreatic dysplasia: a syndrome reconsidered

Five infants, three dying neonatally and two later in the first year of life, had renal, hepatic, and pancreatic dysplasia, a combination of abnormalities first described by Ivemark et al [1959]. The renal malformation consisted of cystic dysplasia, with abnormally differentiated ducts, deficient nephron differentiation, and glomerular cysts. The hepatic abnormality consisted of enlarged portal areas containing numerous elongated biliary "profiles," with a tendency to perilobular fibrosis. Serial liver biopsies in one child with cholestasis from birth showed a progression from bile duct paucity at 1 1/2 wk to typical biliary "dysgenesis" at 7 mo. Four of the five children had intrahepatic ductal dilatation, diagnosed ante mortem in the two older children as Caroli disease. The pancreatic abnormality consisted of fibrosis and cysts, with a diminution of parenchymal tissue. The clinical and functional reflection of these abnormalities in the two children surviving the newborn period included renal insufficiency, chronic jaundice, and insulin-dependent diabetes mellitus. Similar renal, hepatic, and pancreatic abnormalities occur in other syndromes, including trisomy 9, Meckel syndrome, Jeune, Saldino-Noonan, and Elejalde types of chondrodysplasia, and glutaric aciduria II. After exclusion of identifiable syndromes, the remaining cases of renal-hepatic-pancreatic dysplasia do not necessarily constitute a homogeneous group.