Microcephaly, malformation of brain development and intracranial calcification in sibs: Pseudo-TORCH or a new syndrome

Craniofacial and dental features in children aged 3-5 years with congenital Zika syndrome

OBJECTIVE

Zika virus infection has been associated to congenital zika syndrome (CZS) in newborns and is characterized by microcephaly, central/axial motor and sensory dysfunction, dysphagia among other previously described severe health complications. CZS is usually diagnosed postpartum by evident/apparent neural development problems. Although there are some reports of craniofacial/dentition development in CZS, several clinical oral aspects are still unknown. This study describes some structural and functional characteristics of facial and cranial growth and deciduous dentition in CZS-affected children.

MATERIAL AND METHODS

Some cranial, facial and dental characteristics were determined in 14 children with CZS aged 3-5 years and compared them against 12 apparently healthy children paired by age and gender.

RESULTS

Fourteen CZS cases presented microcephaly, maxillary prognathism, altered facial thirds, asymmetric pupillary line, bruxism (p = 0.006), deep and anterior open bite and distal step decidual molar relationship (p = 0.031). CZS children cannot feed by themselves and most cannot walk and have not develop coordinated and intelligible language according to their chronological age. In contrast, controls presented normal skull features, have autonomous locomotion skills, speak intelligible language, feed by themselves, presented a harmonic intermaxillary relationship and have symmetrical facial thirds.

CONCLUSION

Microcephaly, dysphagia, bruxism, mandibular retrognathia, altered facial proportions and malocclusion are the main craniofacial and oral features at CZS.

CLINICAL RELEVANCE

The complications of CZS including those related with the face and the oral cavity are still being identified. This study revealed some cranial, facial and oral features in children affected by CSZ. Interdisciplinary rehabilitation protocols must address these syndromic features that could improve children and parents living conditions.

A Case Report and Literature Review of Pseudo-TORCH Syndrome Type 2 (PTORCH2)

A pseudo-TORCH syndrome is a rare autosomal recessive disease characterized by intracranial calcification and microcephaly, leading to spasticity and seizures, but the serology of TORCH infection is negative. We present a 4-day-old female patient with jaundice, abnormal movement, and convulsions who was found to be homozygous for the missense USP18 gene mutation that causes pseudo-TORCH syndrome 2 (PTORCH2). The patient was managed with conservative measures.

A Fetus with Congenital Microcephaly, Microphthalmia and Cataract Was Detected with Biallelic Variants in the OCLN Gene: A Case Report

Microcephaly and microphthalmia are both rare congenital abnormalities, while concurrently, these two are even rarer. The underlying etiology would be complex interplaying between heterogeneous genetic background and the environmental pathogens, particularly during critical periods of early tissue development. Here, we reported a prenatal case with microcephaly, microphthalmia, and bilateral cataracts detected by ultrasonography and confirmed by autopsy. Various routine infection-related tests and invasive genetic testing were negative. Whole genome sequencing of fetus and parents revealed OCLN gene defects may be associated with these multiple congenital abnormalities.

Phenotypic variability of a TREX1 variant in Aicardi-Goutieres type 1 patients from the Indian subcontinent

Aicardi-Goutieres Syndrome (AGS) is a heterogeneous genetic syndrome, manifesting early as encephalopathy and is associated with abnormal neurologic findings, hepatosplenomegaly, elevated liver enzymes, thrombocytopenia and intracranial calcification. The most severe neonatal type, AGS1, is caused by biallelic disease-causing variants in TREX1. In this study, we describe four patients with TREX1-related AGS1 whose phenotype overlaps with intra-uterine infections and neonatal lupus. Exome sequencing identified a previously reported TREX1 variant, c.223dup (NM_016381.5; p. Glu75GlyfsTer82) in all the four patients belonging to the Indian subcontinent. The functional consequence of the disease-causing variant was predicted by using a new combination of bioinformatics softwares. The recurrence of this pathogenic variant indicates a possible founder effect in TREX1 for AGS1 in this population. The phenotypic variability in those with this founder mutation can mimic intrauterine infections and neonatal lupus, thereby leading to misdiagnosis warranting a targeted genetic testing approach to be a part of the diagnostic workup to obtain a definite, early and cost-effective diagnosis in patients from Indian subcontinent with early onset encephalopathy.

Congenital microcephaly: A diagnostic challenge during Zika epidemics

The multiple, wide and diverse etiologies of congenital microcephaly are complex and multifactorial. Recent advances in genetic testing have improved understanding of novel genetic causes of congenital microcephaly. The recent Zika virus (ZIKV) epidemic in Latin America has highlighted the need for a better understanding of the underlying pathological mechanisms of microcephaly including both infectious and non-infectious causes. The diagnostic approach to microcephaly needs to include potential infectious and genetic etiologies, as well as environmental in-utero exposures such as alcohol, toxins, and medications. Emerging genetic alterations linked to microcephaly include abnormal mitotic microtubule spindle structure and abnormal function of centrosomes. We discuss the diagnostic challenge of congenital microcephaly in the context of understanding the links with ZIKV emergence as a new etiological factor involved in this birth defect.

The phenotypic spectrum of congenital Zika syndrome

In October 2015, Zika virus (ZIKV) outbreak the Brazilian Ministry of Health (MoH). In response, the Brazilian Society of Medical Genetics established a task force (SBGM-ZETF) to study the phenotype of infants born with microcephaly due to ZIKV congenital infection and delineate the phenotypic spectrum of this newly recognized teratogen. This study was based on the clinical evaluation and neuroimaging of 83 infants born during the period from July, 2015 to March, 2016 and registered by the SBGM-ZETF. All 83 infants had significant findings on neuroimaging consistent with ZIKV congenital infection and 12 had confirmed ZIKV IgM in CSF. A recognizable phenotype of microcephaly, anomalies of the shape of skull and redundancy of the scalp consistent with the Fetal Brain Disruption Sequence (FBDS) was present in 70% of infants, but was most often subtle. In addition, features consistent with fetal immobility, ranging from dimples (30.1%), distal hand/finger contractures (20.5%), and feet malpositions (15.7%), to generalized arthrogryposis (9.6%), were present in these infants. Some cases had milder microcephaly or even a normal head circumference (HC), and other less distinctive findings. The detailed observation of the dysmorphic and neurologic features in these infants provides insight into the mechanisms and timings of the brain disruption and the sequence of developmental anomalies that may occur after prenatal infection by the ZIKV.

Band-like calcification with simplified gyration and polymicrogyria: report of 10 new families and identification of five novel OCLN mutations

Band-like calcification with simplified gyration and polymicrogyria (BLC-PMG) is an extremely rare autosomal recessive disorder with distinctive clinical and neuroimaging findings. To date, only 17 patients from 9 unrelated families with BLC-PMG have been reported worldwide. Herein, we describe a series of 13 new patients derived from 10 unrelated Egyptian families. Patients presented at early life with the classic phenotype including severe microcephaly, failure to acquire developmental skills, growth failure and the distinguished calcification patterns involving the cortex, thalami, basal ganglia and pons. Additional features not reported before included calcification of the cerebellum (eight patients: 61.5%) and imperforate anus and undescended testis in a single patient. Molecular studies of the OCLN gene (NM_001205254) identified six distinct candidate mutations. Interestingly, the deletion mutation of the transmembrane domain in exons 3 and 4 (c.51-?_730-?del, p.Lys18_Glu243) was found in five unrelated families (50%), suggesting a founder mutation in our population. On the other hand, five novel truncating mutations (c.809delA (p.K270Rfs*62), c.858_861delTTAT (p.I286Mfs*45), c.1037+5G>C, c.1169C>G (p.S390*) and c.1180delG (p.E394Sfs*91)) were detected, each in one family. To our knowledge, this is the largest series of patients with BLC-PMG. Cerebellum calcification is an additional relevant finding in our series, thus expanding the neuroradiological phenotype of this syndrome.

Renal dysfunction in sibs with band like calcification with simplified gyration and polymicrogyria: Report of a new mutation and review of literature

Band like calcification with simplified gyration and polymicrogyria (BLC-PMG) is a distinct neuroradiological phenotype initially reported as a pseudo-TORCH syndrome and known to result from biallelic mutations in the Occludin(OCLN) gene. This is report of a family of Indian origin with two affected sibs and segregation of a homozygous novel OCLN mutation in the exon 3(NG_028291.1(OCLN_v001):c.252delC). A literature review suggests that renal dysfunction may be an unrecognized phenotypic manifestation of OCLN mutations and monitoring for the same should form part of the clinical care of these individuals.

Fetal brain disruption sequence versus fetal brain arrest: A distinct autosomal recessive developmental brain malformation phenotype

The term fetal brain disruption sequence (FBDS) was coined to describe a number of sporadic conditions caused by numerous external disruptive events presenting with variable imaging findings. However, rare familial occurrences have been reported. We describe five patients (two sib pairs and one sporadic) with congenital severe microcephaly, seizures, and profound intellectual disability. Brain magnetic resonance imaging (MRI) revealed unique and uniform picture of underdeveloped cerebral hemispheres with increased extraxial CSF, abnormal gyral pattern (polymicrogyria-like lesions in two sibs and lissencephaly in the others), loss of white matter, dysplastic ventricles, hypogenesis of corpus callosum, and hypoplasia of the brainstem, but hypoplastic cerebellum in one. Fetal magnetic resonance imaging (FMRI) of two patients showed the same developmental brain malformations in utero. These imaging findings are in accordance with arrested brain development rather than disruption. Molecular analysis excluded mutations in potentially related genes such as NDE1, MKL2, OCLN, and JAM3. These unique clinical and imaging findings were described before among familial reports with FBDS. However, our patients represent a recognizable phenotype of developmental brain malformations, that is, apparently distinguishable from either familial microhydranencephaly or microlissencephaly that were collectively termed FBDS. Thus, the use of the umbrella term FBDS is no longer helpful. Accordingly, we propose the term fetal brain arrest to distinguish them from other familial patients diagnosed as FBDS. The presence of five affected patients from three unrelated consanguineous families suggests an autosomal-recessive mode of inheritance. The spectrum of fetal brain disruption sequence is reviewed.

Anaesthetic Management of a Patient with Pseudo-TORCH Syndrome

BACKGROUND

Pseudo-TORCH syndrome is a rare, chronic disorder that is characterised by dimorphic features such as microcephaly, intracranial calcification, seizures, mental retardation, hepatosplenomegaly and coagulation disorders.

CASE REPORT

We present the anaesthetic management of a forty day-old boy with Pseudo-TORCH syndrome during magnetic resonance imaging. Microcephaly, growth failure, high palate and bilateral rales in the lungs were detected in pre-anaesthetic physical examination. The peripheral oxygen saturation was 88-89% in room-air and was 95% in a hood with 5 L/min oxygen. We planned general anaesthesia to ensure immobility during magnetic resonance imaging. After standard monitoring, general anaesthesia was induced with 8% sevoflurane in 100% O2. After an adequate depth of anaesthesia was reached, we inserted a supraglottic airway device to avoid intubation without the use of a muscle relaxant.

CONCLUSION

In patients with Pseudo-TORCH syndrome, the perioperative anaesthetic risk was increased. We believe that using a supraglottic airway device to secure the airway is less invasive than intubation, and can be performed without the need of muscle relaxants.

Delineation of the clinical, molecular and cellular aspects of novel JAM3 mutations underlying the autosomal recessive hemorrhagic destruction of the brain, subependymal calcification, and congenital cataracts

We have recently shown that the hemorrhagic destruction of the brain, subependymal, calcification, and congenital cataracts is caused by biallelic mutations in the gene encoding junctional adhesion molecule 3 (JAM3) protein. Affected members from three new families underwent detailed clinical examination including imaging of the brain. Affected individuals presented with a distinctive phenotype comprising hemorrhagic destruction of the brain, subependymal calcification, and congenital cataracts. All patients had a catastrophic clinical course resulting in death. Sequencing the coding exons of JAM3 revealed three novel homozygous mutations: c.2T>G (p.M1R), c.346G>A (p.E116K), and c.656G>A (p.C219Y). The p.M1R mutation affects the start codon and therefore is predicted to impair protein synthesis. Cellular studies showed that the p.C219Y mutation resulted in a significant retention of the mutated protein in the endoplasmic reticulum, suggesting a trafficking defect. The p.E116K mutant traffics normally to the plasma membrane as the wild-type and may have lost its function due to the lack of interaction with an interacting partner. Our data further support the importance of JAM3 in the development and function of the vascular system and the brain.

Fetal magnetic resonance imaging (MRI): a tool for a better understanding of normal and abnormal brain development

Knowledge of the anatomy of the developing fetal brain is essential to detect abnormalities and understand their pathogenesis. Capability of magnetic resonance imaging (MRI) to visualize the brain in utero and to differentiate between its various tissues makes fetal MRI a potential diagnostic and research tool for the developing brain. This article provides an approach to understand the normal and abnormal brain development through schematic interpretation of fetal brain MR images. MRI is a potential screening tool in the second trimester of pregnancies in fetuses at risk for brain anomalies and helps in describing new brain syndromes with in utero presentation. Accurate interpretation of fetal MRI can provide valuable information that helps genetic counseling, facilitates management decisions, and guides therapy. Fetal MRI can help in better understanding the pathogenesis of fetal brain malformations and can support research that could lead to disease-specific interventions.

Recognizable phenotypes associated with intracranial calcification

AIM

In this observational study, we adopted a systematic approach to the radiological phenotyping of disorders associated with intracranial calcification, with the aim of determining if characteristic patterns could be defined as an aid to the future diagnosis of known conditions and the identification of new disorders.

METHOD

A cranial imaging-based scoring system was devised using both computed tomography and magnetic resonance imaging data. Patients were grouped into diagnostic categories where a definitive molecular diagnosis was known, or where the clinical and radiological features suggested a specific diagnosis. For patients in whom the diagnosis was unknown, subgroups were defined according to shared radiological features.

RESULTS

Data on 244 scans from 119 patients were analysed. A specific diagnosis was available for 59 patients (31 males, 28 females; median age 50 mo, range 1 wk to 54 y). These were as follows (number of patients in brackets): Aicardi-Goutières syndrome (33), cerebroretinal microangiopathy with calcification and cysts (10), band-like calcification with simplified gyration and polymicrogyria (6), COL4A1-related disease (3), Degos disease (2), Krabbe disease (2), Alexander disease (1), mitochondrial disease (1), and tetrasomy 15 (1). In 60 patients the aetiology was unknown. Within this group, subsets demonstrating shared characteristics suggestive of a specific calcification phenotype could be identified.

INTERPRETATION

This study confirms the value of a systematic approach to radiological phenotyping of disorders associated with intracranial calcification.

Aicardi-Goutières syndrome with emphasis on sonographic features in infancy

BACKGROUND

Aicardi-Goutières syndrome (AGS) is a severe familial, mostly autosomal recessive encephalopathy, first described in 1984. The clinical picture and genetic abnormalities are heterogeneous. US findings in AGS have thus far not been systematically described.

OBJECTIVE

The purpose of this study was to analyse sonographic features in AGS and to compare them to CT/MRI.

MATERIALS AND METHODS

Four male infants with AGS, two brothers, underwent imaging between the ages of 4 weeks and 6 months.

RESULTS

Sonographically isolated mineralization of lenticulostriate vessels, dilatation of the lateral ventricles, subependymal cysts, and diffuse and focal hyperechogenicity of the periventricular white matter and basal ganglia, respectively, were the abnormal findings, that may be present even before the development of major neurological symptoms.

CONCLUSION

Early cranial US is able to visualize the whole spectrum of cerebral anomalies in AGS: calcifying microangiopathy, white matter disease and unusual subependymal cysts. The imaging pattern is similar to that of congenital viral infection of the central nervous system, which may mislead the genetic counseling.

Congenital dysplastic microcephaly and hypoplasia of the brainstem and cerebellum with diffuse intracranial calcification

Congenital microcephaly with intracranial calcification is a rare condition presented in heterogeneous diseases. Here, we report the case of a 1-year-old boy with severe congenital microcephaly and diffuse calcification. Neuroimaging studies showed a diffuse simplified gyral pattern; a very thin cortex; ventricular dilatation; very small basal ganglia, thalamus, and brainstem; and cerebellar hypoplasia with diffuse calcification. Clinical features of intrauterine infections, such as neonatal jaundice, hepatomegaly, and thrombocytopenia, were not found. Serological tests, cultures, and polymerase chain reaction analysis were negative for viral infections. The etiology of pseudo-toxoplasmosis, rubella, cytomegalovirus, and herpes simplex syndrome is still unknown. This study describes the most severe form of pseudo-toxoplasmosis, rubella, cytomegalovirus, and herpes simplex syndrome reported to date, with the patient showing microcephaly and calcification or band-like intracranial calcification with simplified gyration and polymirogyria.

Congenital infection-like syndrome with intracranial calcification

Congenital infection-like syndrome includes multiple disorders. Although novel syndromes have recently been described and their genetic defects identified, many cases remain unclassified. Here we report a patient with neuroradiologic findings of intracranial calcification and cerebellar hypoplasia, and clinical features of growth retardation, progressive pancytopenia, interstitial pneumonia, and immune abnormality. Our patient had a phenotypic overlap with Aicardi-Goutières syndrome and Hoyeraal-Hreidarsson syndrome, despite the absence of mutation in their responsible genes.

A homozygous mutation in the tight-junction protein JAM3 causes hemorrhagic destruction of the brain, subependymal calcification, and congenital cataracts

The tight junction, or zonula occludens, is a specialized cell-cell junction that regulates epithelial and endothelial permeability, and it is an essential component of the blood-brain barrier in the cerebrovascular endothelium. In addition to functioning as a diffusion barrier, tight junctions are also involved in signal transduction. In this study, we identified a homozygous mutation in the tight-junction protein gene JAM3 in a large consanguineous family from the United Arab Emirates. Some members of this family had a rare autosomal-recessive syndrome characterized by severe hemorrhagic destruction of the brain, subependymal calcification, and congenital cataracts. Their clinical presentation overlaps with some reported cases of pseudo-TORCH syndrome as well as with cases involving mutations in occludin, another component of the tight-junction complex. However, massive intracranial hemorrhage distinguishes these patients from others. Homozygosity mapping identified the disease locus in this family on chromosome 11q25 with a maximum multipoint LOD score of 6.15. Sequence analysis of genes in the candidate interval uncovered a mutation in the canonical splice-donor site of intron 5 of JAM3. RT-PCR analysis of a patient lymphoblast cell line confirmed abnormal splicing, leading to a frameshift mutation with early termination. JAM3 is known to be present in vascular endothelium, although its roles in cerebral vasculature have not been implicated. Our results suggest that JAM3 is essential for maintaining the integrity of the cerebrovascular endothelium as well as for normal lens development in humans.

Recessive mutations in the gene encoding the tight junction protein occludin cause band-like calcification with simplified gyration and polymicrogyria

Band-like calcification with simplified gyration and polymicrogyria (BLC-PMG) is a rare autosomal-recessive neurological disorder showing highly characteristic clinical and neuroradiological features. Affected individuals demonstrate early-onset seizures, severe microcephaly, and developmental arrest with bilateral, symmetrical polymicrogyria (PMG) and a band of gray matter calcification on brain imaging; as such, the disorder can be considered as a "pseudo-TORCH" syndrome. By using autozygosity mapping and copy number analysis we identified intragenic deletions and mutations in OCLN in nine patients from six families with BLC-PMG. The OCLN gene encodes occludin, an integral component of tight junctions. Neuropathological analysis of an affected individual showed similarity to the mouse model of occludin deficiency with calcification predominantly associated with blood vessels. Both intracranial calcification and PMG are heterogeneous in etiology. Neuropathological and clinical studies of PMG have suggested that in utero ischemic or vascular insults may contribute to this common cortical abnormality. Tight junctions are functional in cerebral blood vessels early in fetal development and continue to play a vital role in maintenance of the blood-brain barrier during postnatal life. We provide evidence that the tight junction protein occludin (encoded by the OCLN gene) is involved in the pathogenesis of malformations of cortical development.

Fetal infections and brain development

Current microbial diagnostics enable rapid and specific identification of the agents causing intrauterine and perinatal infections, and CT and MRI allow precise characterization of the central nervous system effects of these pathogens. Although infections with Toxoplasma gondii, Toxoplasma pallidum, Toxoplasma cruzi, and cytomegalovirus cannot currently be prevented by immunization, postnatal therapy of infected neonates can substantially improve outcome. Therapy with acyclovir should be initiated whenever perinatal herpes simplex virus encephalitis is suspected. Despite these strategies, intrauterine and perinatal infections remain major causes of permanent deafness, vision loss, cerebral palsy, and epilepsy among children throughout the world.