Microcephalic osteodysplastic primordial dwarfism type II: A child with café au lait lesions, cutis marmorata, and moyamoya disease

Microcephalic osteodyplastic primordial dwarfism type II: case report with unique oral findings and a new mutation in the pericentrin gene

OBJECTIVE

Microcephalic osteodysplastic dwarfism (MOPD) type II (OMIM 210720) is a rare autosomal recessive form of primordial dwarfism, characterized by intrauterine and postnatal growth restriction, microcephaly, distinctive facial features, and osteodysplastic skeletal changes. The dental literature describing the oral manifestations of this syndrome is scarce.

STUDY DESIGN

The aim of this article is to report the case of an 8-year-old male of Indian origin with MOPD type II and to describe his oral and dental manifestations. Genetic analysis was performed to confirm the diagnosis.

RESULTS

The patient presented with interesting dental findings, including oligodontia, enamel hypoplasia, early exfoliation of primary dentition, accelerated eruption of permanent teeth with generalized grade II mobility, histopathologic features suggestive of dentin dysplasia, and a new mutation in the Pericentrin gene, which has not been documented earlier.

CONCLUSIONS

This is the first report from India of a case with this syndrome. The article presents various dentomaxillofacial features that have not been documented in dental literature earlier with sufficient evidence.

Majewski dwarfism type II: an atypical neuroradiological presentation with a novel variant in the PCNT gene

Microcephalic osteodysplastic primordial dwarfism syndrome II (MOPDII) is microcephalic primordial dwarfism and is a very rare form of disproportionate short stature. This disorder shares common features with other forms of microcephalic primordial dwarfism, including severe prenatal and postnatal growth retardation with marked microcephaly. However, it includes characteristic skeletal dysplasia, abnormal dentition and increased risk for cerebrovascular diseases. Recent reports added more features, including café-au-lait lesions, cutis marmorata, astigmatism, Moyamoya disease, insulin resistance, obesity, abnormal skin pigmentation and acanthosis nigricans around the neck. Clearly, the more MOPDII reports that are produced, the more information will be added to the spectrum of MOPDII features that can improve our understanding of this disorder. In this paper, we reported a new case of MOPDII with more severe clinical features, earlier onset of common features, in addition to a homozygous novel variant in the PCNT gene.

Microcephalic Osteodysplastic Primordial Dwarfism, Type II: a Clinical Review

PURPOSE OF THE REVIEW

This review will provide an overview of the microcephalic primordial dwarfism (MPD) class of disorders and provide the reader comprehensive clinical review with suggested care guidelines for patients with microcephalic osteodysplastic primordial dwarfism, type II (MOPDII).

RECENT FINDINGS

Over the last 15 years, significant strides have been made in the diagnosis, natural history, and management of MOPDII. MOPDII is the most common and well described form of MPD. The classic features of the MPD group are severe pre- and postnatal growth retardation, with marked microcephaly. In addition to these features, individuals with MOPDII have characteristic facies, skeletal dysplasia, abnormal dentition, and an increased risk for cerebrovascular disease and insulin resistance. Biallelic loss-of-function mutations in the pericentrin gene cause MOPDII, which is inherited in an autosomal recessive manner.

Surgical outcomes of Majewski osteodysplastic primordial dwarfism Type II with intracranial vascular anomalies

OBJECTIVE Majewski osteodysplastic primordial dwarfism Type II (MOPD II) is a rare genetic disorder. Features of it include extremely small stature, severe microcephaly, and normal or near-normal intelligence. Previous studies have found that more than 50% of patients with MOPD II have intracranial vascular anomalies, but few successful surgical revascularization or aneurysm-clipping cases have been reported because of the diminutive arteries and narrow surgical corridors in these patients. Here, the authors report on a large series of patients with MOPD II who underwent surgery for an intracranial vascular anomaly. METHODS In conjunction with an approved prospective registry of patients with MOPD II, a prospectively collected institutional surgical database of children with MOPD II and intracranial vascular anomalies who underwent surgery was analyzed retrospectively to establish long-term outcomes. RESULTS Ten patients with MOPD II underwent surgery between 2005 and 2012; 5 patients had moyamoya disease (MMD), 2 had intracranial aneurysms, and 3 had both MMD and aneurysms. Patients presented with transient ischemic attack (TIA) (n = 2), ischemic stroke (n = 2), intraparenchymal hemorrhage from MMD (n = 1), and aneurysmal subarachnoid hemorrhage (n = 1), and 4 were diagnosed on screening. The mean age of the 8 patients with MMD, all of whom underwent extracranial-intracranial revascularization (14 indirect, 1 direct) was 9 years (range 1-17 years). The mean age of the 5 patients with aneurysms was 15.5 years (range 9-18 years). Two patients experienced postoperative complications (1 transient weakness after clipping, 1 femoral thrombosis that required surgical repair). During a mean follow-up of 5.9 years (range 3-10 years), 3 patients died (1 of subarachnoid hemorrhage, 1 of myocardial infarct, and 1 of respiratory failure), and 1 patient had continued TIAs. All of the surviving patients recovered to their neurological baseline. CONCLUSIONS Patients with MMD presented at a younger age than those in whom aneurysms were more prevalent. Microneurosurgery with either intracranial bypass or aneurysm clipping is extremely challenging but feasible at expert centers in patients with MOPD II, and good long-term outcomes are possible.

Majewski osteodysplastic primordial dwarfism type II: clinical findings and dental management of a child patient

Majewski osteodysplastic primordial dwarfism type II (MOPD II) is an unusual autosomal recessive inherited form of primordial dwarfism, which is characterized by a small head diameter at birth, but which also progresses to severe microcephaly, progressive bony dysplasia, and characteristic facies and personality. This report presents a case of a five-year-old girl with MOPD II syndrome. The patient was referred to our clinic with the complaint of severe tooth pain at the left mandibular primary molar teeth. Clinical examination revealed that most of the primary teeth had been decayed and all primary teeth were hypoplastic. Patient’s history revealed delayed development in the primary dentition and radiographic examination showed rootless primary molar teeth and short-rooted incisors. The treatment was not possible due to the lack of root of the left mandibular primary molars; so the teeth were extracted. Thorough and timely dental evaluation is crucial for the prevention of dental problems and the maintenance of oral health in patients with MOPD II syndrome is of utmost importance.

Screening for cerebrovascular disease in microcephalic osteodysplastic primordial dwarfism type II (MOPD II): an evidence-based proposal

Microcephalic osteodysplastic primordial dwarfism type II (OMIM 210720) is a rare autosomal recessive condition frequently associated with early-onset cerebrovascular disease. Presymptomatic detection and intervention could prevent the adverse consequences associated with this. We reviewed published cases of microcephalic osteodysplastic primordial dwarfism type II to ascertain prevalence and characteristics of cerebrovascular disease and use these data to propose an evidence-based approach to cerebrovascular screening. Of 147 cases identified, 47 had cerebrovascular disease (32%), including occlusive arteriopathy (including moyamoya) and cerebral aneurysmal disease. Occlusive disease occurred in younger individuals, and progression can be both rapid and clinically silent. A reasonable screening approach would be magnetic resonance imaging and angiography of the cervical and intracranial circulation at diagnosis, repeated at yearly intervals until 10 years, and every 2 years thereafter, unless clinical concerns occur earlier. At present it would appear that this needs to be life-long. Families and professionals should be alerted to the potential significance of neurologic symptoms and measures should be taken to maintain good vascular health in affected individuals.

Clinical and functional characterization of a patient carrying a compound heterozygous pericentrin mutation and a heterozygous IGF1 receptor mutation

Intrauterine and postnatal longitudinal growth is controlled by a strong genetic component that regulates a complex network of endocrine factors integrating them with cellular proliferation, differentiation and apoptotic processes in target tissues, particularly the growth centers of the long bones. Here we report on a patient born small for gestational age (SGA) with severe, proportionate postnatal growth retardation, discreet signs of skeletal dysplasia, microcephaly and moyamoya disease. Initial genetic evaluation revealed a novel heterozygous IGF1R p.Leu1361Arg mutation affecting a highly conserved residue with the insulin-like growth factor type 1 receptor suggestive for a disturbance within the somatotropic axis. However, because the mutation did not co-segregate with the phenotype and functional characterization did not reveal an obvious impairment of the ligand depending major IGF1R signaling capabilities a second-site mutation was assumed. Mutational screening of components of the somatotropic axis, constituents of the IGF signaling system and factors involved in cellular proliferation, which are described or suggested to provoke syndromic dwarfism phenotypes, was performed. Two compound heterozygous PCNT mutations (p.[Arg585X];[Glu1774X]) were identified leading to the specification of the diagnosis to MOPD II. These investigations underline the need for careful assessment of all available information to derive a firm diagnosis from a sequence aberration.

Neuronal migration disorders in microcephalic osteodysplastic primordial dwarfism type I/III

Microcephalic osteodysplastic primordial dwarfism (MOPD) is a rare microlissencephaly syndrome, with at least two distinct phenotypic and genetic types. MOPD type II is caused by pericentrin mutations, while types I and III appear to represent a distinct entity (MOPD I/III) with variably penetrant phenotypes and unknown genetic basis. The neuropathology of MOPD I/III is little understood, especially in comparison to other forms of lissencephaly. Here, we report postmortem brain findings in an 11-month-old female infant with MOPD I/III. The cerebral cortex was diffusely pachygyric, with a right parietal porencephalic lesion. Histologically, the cortex was abnormally thick and disorganized. Distinct malformations were observed in different cerebral lobes, as characterized using layer-specific neuronal markers. Frontal cortex was severely disorganized and coated with extensive leptomeningeal glioneuronal heterotopia. Temporal cortex had a relatively normal 6-layered pattern, despite cortical thickening. Occipital cortex was variably affected. The corpus callosum was extremely hypoplastic. Brainstem and cerebellar malformations were also present, as well as old necrotic foci. Findings in this case suggest that the cortical malformation in MOPD I/III is distinct from other forms of pachygyria-lissencephaly.

Moyamoya-like vasculopathy and Seckel syndrome: just a coincidence?

INTRODUCTION

Seckel syndrome (SS) and other microcephalic primordial dwarfisms (MPDs) are a group of autosomal recessive disorders characterized by prenatal and postnatal growth retardation, microcephaly, and distinct facial dysmorphic features. There are an increasing number of reports in the literature linking MPDs with cerebrovascular anomalies, including intracranial aneurysms and moyamoya.

CASE REPORT

An 18-year-old female patient with SS and mental retardation was referred for spontaneous subarachnoid hemorrhage. At the age of 3 years, she had suffered multifocal ischemic cerebrovascular accidents following an elective urological procedure. Cardiac, hematologic, and serologic workups were negative, and cerebral angiography was recommended but declined by the parents. Brain MRA and cerebral angiography showed bilateral narrowing of extracranial and intracranial internal carotid arteries (ICAs), obliteration of the right supraclinoid ICA without moya-moya collaterals, and multiple bilateral saccular aneurysms on the hypertrophied posterior cerebral arteries. Considering the patient's previous quality of life and the high risks of either endovascular or surgical treatment, all invasive treatments were withheld at the parents' request and only palliative care was offered.

CONCLUSION

It appears that patients with MPD are prone to the development of cerebrovascular anomalies. Therefore, imaging of cerebral vessels should be performed when such patients present with cerebral ischemia or stroke.

Review and hypothesis: syndromes with severe intrauterine growth restriction and very short stature--are they related to the epigenetic mechanism(s) of fetal survival involved in the developmental origins of adult health and disease?

Diagnosing the specific type of severe intrauterine growth restriction (IUGR) that also has post-birth growth restriction is often difficult. Eight relatively common syndromes are discussed identifying their unique distinguishing features, overlapping features, and those features common to all eight syndromes. Many of these signs take a few years to develop and the lifetime natural history of the disorders has not yet been completely clarified. The theory behind developmental origins of adult health and disease suggests that there are mammalian epigenetic fetal survival mechanisms that downregulate fetal growth, both in order for the fetus to survive until birth and to prepare it for a restricted extra-uterine environment, and that these mechanisms have long lasting effects on the adult health of the individual. Silver-Russell syndrome phenotype has recently been recognized to be related to imprinting/methylation defects. Perhaps all eight syndromes, including those with single gene mutation origin, involve the mammalian mechanism(s) of fetal survival downsizing. Insights into those mechanisms should provide avenues to understanding the natural history, the heterogeneity and possible therapy not only for these eight syndromes, but for the common adult diseases with which IUGR is associated.

Moyamoya disease in children with congenital dwarfing conditions

Congenital dwarfisms can be associated with a variety of vascular anomalies. Here, we describe 2 patients with congenital dwarfisms who presented with moyamoya syndrome and underwent indirect intracranial revascularization. The pathogenesis of moyamoya syndrome in this population is not well understood, but it is a major cause of stroke and early death in these patients, making their timely diagnosis and management critical.

Multiple intracranial aneurysms and moyamoya disease associated with microcephalic osteodysplastic primordial dwarfism type II: surgical considerations

Microcephalic osteodysplastic primordial dwarfism type II (MOPD II) is a rare genetic syndrome characterized by extremely small stature and microcephaly, and is associated in 25% of patients with intracranial aneurysms and moyamoya disease. Although aneurysmal subarachnoid hemorrhage and stroke are leading causes of morbidity and death in these patients, MOPD II is rarely examined in the neurosurgical literature. The authors report their experience with 3 patients who presented with MOPD II, which includes a patient with 8 aneurysms (the most aneurysms reported in the literature), and the first report of a patient with both moyamoya disease and multiple aneurysms. The poor natural history of these lesions indicates aggressive microsurgical and/or endovascular therapy. Microsurgery, whether for aneurysm clip placement or extracranial-intracranial bypass, is challenging due to tight surgical corridors and diminutive arteries in these patients, but is technically feasible and strongly indicated when multiple aneurysms must be treated or cerebral revascularization is needed.

Mutation in pyrroline-5-carboxylate reductase 1 gene in families with cutis laxa type 2

Autosomal-recessive cutis laxa type 2 (ARCL2) is a multisystem disorder characterized by the appearance of premature aging, wrinkled and lax skin, joint laxity, and a general developmental delay. Cutis laxa includes a family of clinically overlapping conditions with confusing nomenclature, generally requiring molecular analyses for definitive diagnosis. Six genes are currently known to mutate to yield one of these related conditions. We ascertained a cohort of typical ARCL2 patients from a subpopulation isolate within eastern Canada. Homozygosity mapping with high-density SNP genotyping excluded all six known genes, and instead identified a single homozygous region near the telomere of chromosome 17, shared identically by state by all genotyped affected individuals from the families. A putative pathogenic variant was identified by direct DNA sequencing of genes within the region. The single nucleotide change leads to a missense mutation adjacent to a splice junction in the gene encoding pyrroline-5-carboxylate reductase 1 (PYCR1). Bioinformatic analysis predicted a pathogenic effect of the variant on splice donor site function. Skipping of the associated exon was confirmed in RNA from blood lymphocytes of affected homozygotes and heterozygous mutation carriers. Exon skipping leads to deletion of the reductase functional domain-coding region and an obligatory downstream frameshift. PYCR1 plays a critical role in proline biosynthesis. Pathogenicity of the genetic variant in PYCR1 is likely, given that a similar clinical phenotype has been documented for mutation carriers of another proline biosynthetic enzyme, pyrroline-5-carboxylate synthase. Our results support a significant role for proline in normal development.

Seckel syndrome and moyamoya

Seckel syndrome is an autosomal recessive disorder characterized by intrauterine and postnatal growth delay, microcephaly with mental retardation, and facial dysmorphisms including micrognathia, a recessed forehead, and a large beaked nose. Occurring in 1 in 10,000 children without sex preference, it is the most common primordial microcephalic osteodysplastic dwarfism and has been associated with a variety of congenital brain malformations and intracranial aneurysms. Moyamoya syndrome is an idiopathic, chronic, progressive cerebrovascular disorder marked by stenosis of the intracranial internal carotid arteries and concurrent development of hypertrophied collateral vessels. These tortuous arterial collaterals appear radiographically as "puffs of smoke," giving the syndrome its name. In this report, the authors describe the case of a 16-year-old girl with coincident Seckel and moyamoya syndromes. To their knowledge, this is the first reported case of such an association being treated with surgical revascularization. The patient presented with persistent headaches and a 2-year history of progressive hand, arm, and face numbness. Imaging studies revealed multiple completed cerebral infarcts, global ischemic changes, and vascular anatomy consistent with moyamoya syndrome. Bilateral pial synangioses successfully revascularized each hemisphere with resolution of the patient's symptoms. The patient died 1 year later of complications related to treatment of a rapidly progressing intracranial aneurysm. This report documents the first case associating moyamoya and Seckel syndromes. In addition, the report reveals the rapid development of an intracranial aneurysm in a patient with this syndrome. When coupled with previous reports of other types of cerebrovascular disease in patients with Seckel syndrome or other primordial dwarfisms, the authors' findings are important because they suggest that physicians treating patients with dwarfism should consider the diagnosis of moyamoya syndrome when symptoms suggestive of cerebral ischemia are present. Prompt diagnosis and treatment of moyamoya syndrome, including the use of proven surgical revascularization procedures such as pial synangiosis, may significantly improve the long-term outcomes of these patients.

Neurologic aspects of microcephalic osteodysplastic primordial dwarfism type II

Microcephalic osteodysplastic primordial dwarfism type II is a specific disorder characterized by severe intrauterine and postnatal growth retardation, acquired microcephaly, cerebrovascular abnormalities, progressive bone dysplasia, and a characteristic face. Whereas the diagnostic features of this syndrome are well-recognized, the neurologic aspects have not been clearly defined. We report on a detailed neurodevelopmental follow-up study of a new case of microcephalic osteodysplastic primordial dwarfism type II, followed from the first years of life to adolescence, and we discuss the neurocognitive features of our patient. We also review the neurologic aspects of this disorder compared with syndromes with overlapping phenotypes, such as microcephalic osteodysplastic primordial dwarfism types I and III and Seckel syndrome.

Majewski osteodysplastic primordial dwarfism type II (MOPD II) complicated by stroke: clinical report and review of cerebral vascular anomalies

We report on a 2 9/12-year-old boy with disproportionate short stature, microcephaly, subtle craniofacial dysmorphisms, and generalized skeletal dysplasia, who developed a left hemiparesis. Brain neuroimaging disclosed a complex cerebral vascular anomaly (CVA) with stenosis of the right anterior cerebral artery and telangiectatic collateral vessels supplying the cerebral cortex, consistent with moyamoya disease. Based on clinical and skeletal features, a diagnosis of Majewski osteodysplastic primordial dwarfism type II (MOPD II) was established. Review of 16 published patients with CVA affected by either Seckel syndrome or MOPD II suggested that CVA is preferentially associated to the latter subtype affecting about 1/4 of the patients.