Hypogenesis Of Corpus Callosum Research Articles

Refining the phenotypic spectrum of CCDC88A-related PEHO-like syndrome.

Progressive encephalopathy with edema, hypsarrhythmia, and optic atrophy (PEHO) and PEHO-like syndromes are very rare infantile disorders characterized by profound intellectual disability, hypotonia, convulsions, optic, and progressive brain atrophy. Many causative genes for PEHO and PEHO-like syndromes have been identified including CCDC88A. So far, only five patients from two unrelated families with biallelic CCDC88A variants have been reported in the literature. Herein, we describe a new family from Egypt with a lethal epileptic encephalopathy. Our patient was the youngest child born to a highly consanguineous couple and had a family history of five deceased sibs with the same condition. She presented with postnatal microcephaly, poor visual responsiveness, and epilepsy. Her brain MRI showed abnormal cortical gyration with failure of opercularization of the insula, hypogenesis of corpus callosum, colpocephaly, reduced white matter, hypoplastic vermis, and brain stem. Whole exome sequencing identified a new homozygous frameshift variant in CCDC88A gene (c.1795_1798delACAA, p.Thr599ValfsTer4). Our study presents the third reported family with this extremely rare disorder. We also reviewed all described cases to better refine the phenotypic spectrum associated with biallelic loss of function variants in the CCDC88A gene.

Delineating FOXG1 syndrome: From congenital microcephaly to hyperkinetic encephalopathy.

ObjectiveTo provide new insights into the FOXG1-related clinical and imaging phenotypes and refine the phenotype-genotype correlation in FOXG1 syndrome.MethodsWe analyzed the clinical and imaging phenotypes of a cohort of 45 patients with a pathogenic or likely pathogenic FOXG1 variant and performed phenotype-genotype correlations.ResultsA total of 37 FOXG1 different heterozygous mutations were identified, of which 18 are novel. We described a broad spectrum of neurodevelopmental phenotypes, characterized by severe postnatal microcephaly and developmental delay accompanied by a hyperkinetic movement disorder, stereotypes and sleep disorders, and epileptic seizures. Our data highlighted 3 patterns of gyration, including frontal pachygyria in younger patients (26.7%), moderate simplified gyration (24.4%) and mildly simplified or normal gyration (48.9%), corpus callosum hypogenesis mostly in its frontal part, combined with moderate-to-severe myelination delay that improved and normalized with age. Frameshift and nonsense mutations in the N-terminus of FOXG1, which are the most common mutation types, show the most severe clinical features and MRI anomalies. However, patients with recurrent frameshift mutations c.460dupG and c.256dupC had variable clinical and imaging presentations.ConclusionsThese findings have implications for genetic counseling, providing evidence that N-terminal mutations and large deletions lead to more severe FOXG1 syndrome, although genotype-phenotype correlations are not necessarily straightforward in recurrent mutations. Together, these analyses support the view that FOXG1 syndrome is a specific disorder characterized by frontal pachygyria and delayed myelination in its most severe form and hypogenetic corpus callosum in its milder form.

Cytogenomic characterization of 1q43q44 deletion associated with 4q32.1q35.2 duplication and phenotype correlation

BackgroundMicrodeletion of 1q43q44 causes a syndrome characterized by intellectual disability (ID), speech delay, seizures, microcephaly (MIC), corpus callosum abnormalities (CCA) and characteristic facial features. Duplication of 4q is presented with minor to severe ID, MIC and facial dysmorphism. We aimed to verify the correlation between genotype/phenotype in a patient with 1q43q44 deletion associated with 4q32.1q35.2 duplication.Case presentationWe report on a 3 year-old female patient with delayed motor and mental milestones, MIC and facial dysmorphism. She is a child of non-consanguineous parents and no similarly affected family members. CT brain showed abnormal gyral patterns, hypogenesis of corpus callosum and bilateral deep Sylvian fissure. Electroencephalogram showed frontotemporal epileptogenic focus. Her karyotype was revealed as 46,XX,add(1)(q44). Fluorescence in situ hybridization (FISH) using whole chromosome paint (WCP1) and subtelomere 1q revealed that the add segment was not derived from chromosome 1 and there was the deletion of subtelomere 1q. Multiple ligation probe amplification (MLPA) subtelomere kit revealed the deletion of 1q and duplication of 4q. Array CGH demonstrated the 6.5 Mb deletion of 1q and 31 Mb duplication of chromosome 4q.ConclusionThe phenotype of our patient mainly reflects the effects of haploinsufficiency of AKT3, HNRNPU, ZBTB18 genes associated with duplication of GLRA3, GMP6A, HAND2 genes. Patients presented with ID, seizures, MIC together with CCA are candidates for prediction of 1q43q44 microdeletion and cytogenomic analysis.

Identification of a de novo microdeletion 1q44 in a patient with hypogenesis of the corpus callosum, seizures and microcephaly – A case report

Microdeletion 1q44 on the long arm of chromosome 1 leads to a phenotype that includes microcephaly, seizure, agenesis or hypogenesis of the corpus callosum, polydactyly, congenital heart defects and severe developmental delay along with characteristic facial dysmorphic signs. Until today, the distinct genetic causes for the different symptoms remain unclear.We here report a 1.2Mb de novo microdeletion 1q44 identified by performing a SNP array analysis. The female patient presented with microcephaly, seizure, hypogenesis of corpus callosum, postaxial hexadactyly, an atrial septal defect, a ventricular septal defect, hypertelorism, a long and smooth philtrum, thin vermilion borders, and micrognathia, all common features of microdeletion 1q44. An additionally performed chromosome analysis excluded any chromosomal rearrangements. The deleted region included the genes ZBTB18 as well as HNRNPU amongst others. Both are possibly candidate genes for the dysgenesis of the corpus callosum. AKT3, another candidate gene, was not affected by the deletion in this patient.Thus, the genetic findings in this case report spotlight ZBTB18 and HNRNPU in the genesis of the typical microdeletion 1q44 symptoms, especially concerning the dysgenesis of the corpus callosum, and therefore could help to unveil more of the genetic background of this syndrome.

Cochlear implantation in a child with subtelomeric 1q deletion syndrome and Dandy–Walker malformation

Abstract Subtelomeric 1q deletion syndrome is a rare disorder characterized by severe mental and growth retardation, microcephaly, distinct facial features and corpus callosum abnormalities. Senserineural hearing loss is not common in this syndrome. We report a 2-year-old boy with subtelomeric 1q deletion syndrome presented with typical craniofacial abnormalities and bilateral senserineural hearing loss. Imaging revealed corpus callosum hypogenesis and Dandy-Walker malformation. Cochlear implantation was successfully undertaken using a transmastoid facial recess aproach. After 12-months post-implantation, good audiological outcomes were obtained. Cochlear implantation can be considered for hearing rehabilitation in patients with subtelomeric 1q deletion syndrome and Dandy-Walker malformation.

P77 – 2515: Case of generalized osteopetrosis (marble disease) associated with neurological impairment

Objective Marble bone disease is an inherited condition, characterized by diffuse hardening of bones, their brittleness due to malfunction of osteoclasts. Secondary to bone expansion bone marrow narrows, extramedullar hemopoesis develops, nerves injury might happen. Mutations in 9 genes had been described. CLCN7 mutation leads to 75% cases of autosomal dominant osteopetrosis with benign course, 10 to 15% cases are autosomal recessive with malignant course. Methods A child was born uneventfully from healthy, non-consanguineous parents. First signs of illness appeared at 10 weeks when parents noted tense fontanelle, child became very irritated, horizontal nystagmus appeared, development had stopped. At 6 months the child neither fixed nor followed, but reacted positively to the mother's voice, smiled, had horizontal nystagmus, tetraparesis, diffuse hypotonia, high tendon reflexes, head circumference – 40 cm. Brain MRI showed signs of Chiari I malformation, hypogenesis of corpus callosum, ventriculodilation of lateral ventriculi (12 mm on the level of frontal horn) dilation of fronto – temporal subarhnoid spaces of 7–8 mm, decreased volume of white matter, cerebellum tonsillar herniation of 6 mm. Laboratory finding showed: LDH – 1093, AST – 103, Hgb – 81 g/l, Plt – 72×10 9 /l, WBC under 3×10 9 /l, Chitotriosidase 80 (78–120) nmol/g/mg/protein. USD demonstrated tenfold increasing of spleen size. EMG showed secondary myopathic syndrome. X-ray revealed typical sign of osteopetrosis – “bone in bone” syndrome, clavate thickening of metaphyses, ostesclerosis of pelvis and femurs. Horizontal nystagmus, partial atrophy of optic nerves. Results We made the diagnosis of generalized osteopetrosis, autosomal recessive form, hematology syndrome (anemia, thrombocytopenia, hepatosplenomegaly), bones deformities, development retardation. Genetic risk for sibs is 25%. The disease had malignant course. Despite symptomatic treatment the child had died aged 17 months. Conclusion Presented case of generalized osteopetrosis illustrates progressive course of the disease, with hematologic syndrome and involvement of neurological system, that lead to first presentation of the patient to neurology clinic

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.

The Utility of the Hypsarrhythmia Paroxysm Index and Sleep Spindles in EEG for Predicting Cognitive Outcomes in a Case Series of Infantile Spasms

Objectives: Among patients with West Syndrome (WS), the underlying brain dysfunction is considered to be the major determinant of cognitive outcome. However, regardless of whether the WS type is symptomatic or cryptogenic, patients with infantile spasms may have a favourable or grim prognosis. The purpose of this study was to utilize electroencephalography (EEG) to guide treatment, and to assess cognitive outcome. Methods: We retrospectively reviewed the clinical and sleep EEG data in 16 patients who received adrenocorticotropic hormonal therapy between 2002 and 2014. The hypsarrhythmia paroxysm index (HPI), the frequency or duration of hypsarrhythmia paroxysms in non-rapid eye movement (NREM) sleep, and sleep spindles were evaluated in groups constituted according to etiology. Results: Cryptogenic patients whose onset of spasms began after 3 months of age and who experienced a shorter treatment delay had preserved spindles and favourable cognitive outcomes. Sleep spindles disappeared in cryptogenic patients with an early onset of spasms, long treatment delay, and high HPI at referral; their neurodevelopmental prognosis was unfavourable. In symptomatic cases in which the age of onset of spasms was earlier than 3 months and there had been a short treatment delay, sleep spindles never fully evolved, and the prognosis was poor. Patients with corpus callosum hypogenesis, a relatively mild malformation, had high HPI values at referral. While two of these patients did not display spindles during the follow-up, three had reappearing spindles as HPI values diminished, and the outcome was less severe in these patients. Conclusion: This study highlights the significance of EEG in studies of the prognosis of infantile spasms and demonstrates an objective approach that utilizes concurrent evaluation of sleep spindles and HPI.

Simplified gyral pattern with cerebellar hypoplasia in Sedaghatian type spondylometaphyseal dysplasia: A clinical report and review of the literature

We report on a patient with Sedaghatian type spondylometaphyseal dysplasia (SSMD) who presented with metaphyseal dysplasia, congenital atrioventricular block, simplified gyral pattern, hypogenesis of corpus callosum, and severe cerebellar hypoplasia. We want to emphasize that in this rare congenital lethal skeletal dysplasia with unknown etiology, central nervous system malformations might be a major component of the disorder and should be evaluated in detail to possibly uncover the underlying pathophysiology.

Chromosome 1p32-p31 deletion syndrome: Prenatal diagnosis by array comparative genomic hybridization using uncultured amniocytes and association with NFIA haploinsufficiency, ventriculomegaly, corpus callosum hypogenesis, abnormal external genitalia, and intrauterine growth restriction

Objective To present prenatal diagnosis of chromosome 1p32-p31 deletion syndrome with NFIA haploinsufficiency, ventriculomegaly, corpus callosum hypogenesis, abnormal external genitalia, and intrauterine growth restriction and to review the literature. Materials, Methods, and Results A 26-year-old, primigravid woman was referred for amniocentesis at 30 weeks of gestation because of hydrocephalus and short limbs. Prenatal ultrasound showed macrocephaly, prominent forehead, ventriculomegaly, corpus callosum hypogenesis, micrognathia, and ambiguous external genitalia. Amniocentesis was performed, and array comparative genomic hybridization using uncultured amniocytes revealed a 22.2-Mb deletion of 1p32.3-p31.1 [arr cgh 1p32.3p31.1 (55,500,291 bp–77,711,982 bp)×1] encompassing the genes of NFIA, GPR177, and 89 additional genes. Cytogenetic analysis revealed a karyotype of 46,XX,del(1)(p31.1p32.3)dn. At 33 weeks of gestation, a dead fetus was delivered with a body weight of 1536 g (<5 th centile); relative macrocephaly; a broad face; prominent forehead; hypertelorism; anteverted nostrils; micrognathia; low-set ears; and abnormal female external genitalia with labial fusion, labial hypertrophy, absence of vaginal opening, and clitoral hypertrophy. Polymorphic DNA marker analysis determined a paternal origin of the deletion. Conclusion Prenatal diagnosis of ventriculomegaly with an abnormal corpus callosum should alert subtle chromosome aberrations and prompt molecular cytogenetic investigation if necessary. Fetuses with chromosome 1p32-p31 deletion syndrome and haploinsufficiency of the NFIA gene may present ventriculomegaly, corpus callosum hypogenesis, abnormal external genitalia, and intrauterine growth restriction in the third trimester.

The core FOXG1 syndrome phenotype consists of postnatal microcephaly, severe mental retardation, absent language, dyskinesia, and corpus callosum hypogenesis

BackgroundSubmicroscopic deletions in 14q12 spanning FOXG1 or intragenic mutations have been reported in patients with a developmental disorder described as a congenital variant of Rett syndrome. This study aimed to...

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

We report on five sibs affected by congenital microcephaly, growth retardation, sloping forehead, bitemporal grooving and micrognathia. Generalized tonic-clonic seizures started very early in life. Postnatal brain computerized tomography (CT) presented cortical band-like calcification, calcification of basal ganglia and brain stem while brain magnetic resonance imaging (MRI) revealed abnormal gyral pattern, marked loss of white matter, dysplastic ventricles, polymicrogyria, hypogenesis of corpus callosum and cerebellar hypoplasia. No abnormalities of the internal organs, eye, or skeleton were found to be associated with this syndrome. Fetal Magnetic resonance imaging helped reaching the diagnosis in utero in one patient. Three patients died in the first years of life while the others within days after birth preceded by high fever and status epilepticus. These patients present many overlapping features with pseudo TORCH syndrome, however, the imaging findings are quite different. We propose that the distinct pattern in these sibs constitutes genetic disorder of microcephaly, developmental brain malformation and intracranial calcification of likely autosomal recessive inheritance.

Neuroendoscopic management of interhemispheric cysts in children

Object Interhemispheric arachnoid cysts are very rare, and they are often associated with complex brain malformations such as corpus callosum agenesis and hydrocephalus. Debate remains concerning the proper management of these lesions. Placement of shunts and microsurgical marsupialization of the cyst are the traditional options. Using endoscopic methods to create areas of communication between the cyst, the ventricular system, and/or the subarachnoid space is an attractive alternative to the use of shunts and microsurgery. Methods Between 2000 and 2005, seven consecutive pediatric patients with interhemispheric arachnoid cysts underwent neuroendoscopic treatment involving cystoventriculostomy in two patients, cystocisternostomy in two, and cystoventriculocisternostomy in three. There were three cases of associated hydrocephalus, six cases of corpus callosum agenesis, and one case of corpus callosum hypogenesis. The follow-up period ranged from 12 to 49 months (mean 31.6 months). Endoscopic procedures were completely successful in all but two patients. In one of the remaining two patients, a repeated endoscopic cystocisternostomy was performed with success because of closure of the previous stoma. In the other, a subcutaneous collection of cerebrospinal fluid (CSF) was managed by insertion of a lumboperitoneal shunt. A subdural collection of CSF developed in three patients; it was treated with insertion of a subduroperitoneal shunt in one patient and managed conservatively in the other two patients, resolving spontaneously without further treatment. Neurodevelopmental evaluation performed in six patients showed normal intelligence (total intelligence quotient [IQ] &gt; 80) in three patients, mild developmental delay (total IQ 50–80) in two, and severe developmental delay (total IQ &lt; 50) in one. Conclusions Endoscopic treatment of interhemispheric cysts can be considered a useful alternative to traditional treatments, even if some complications are to be expected, such as subdural or subcutaneous CSF collections and CSF leaks due to thinness of cerebral mantle and to the often-associated multifactorial hydrocephalus.

Rhombencephalosynapsis diagnosed in childhood: Clinical and MRI findings

Rhombencephalosynapsis (RES) is a rare cerebellar malformation of unknown etiology characterized by vermal agenesis or hypogenesis, fusion of hemispheres and the dentate nuclei. Clinical presentation and prognosis are extremely variable and generally depends one the associated supratentorial anomalies. We report the first Tunisian case of RES diagnosed by magnetic resonance imaging (MRI) in a 3.5-year-old boy born to consanguineous parents. The child had spastic diplegia, facial dysmorphia, skeletal anomalies and normal intellectual development. Additional supratentorial anomalies were agenesis of septum pellucidum, moderate hydrocephalus and hypogenesis of corpus callosum. In this paper, the clinical and MRI findings and possible pathogenesis of this disorder are discussed.

Neuroendoscopic management of interhemispheric cysts in children

Interhemispheric arachnoid cysts are very rare, and they are often associated with complex brain malformations such as corpus callosum agenesis and hydrocephalus. Debate remains concerning the proper management of these lesions. Placement of shunts and microsurgical marsupialization of the cyst are the traditional options. Using endoscopic methods to create areas of communication between the cyst, the ventricular system, and/or the subarachnoid space is an attractive alternative to the use of shunts and microsurgery. Between 2000 and 2005, seven consecutive pediatric patients with interhemispheric arachnoid cysts underwent neuroendoscopic treatment involving cystoventriculostomy in two patients, cystocisternostomy in two, and cystoventriculocisternostomy in three. There were three cases of associated hydrocephalus, six cases of corpus callosum agenesis, and one case of corpus callosum hypogenesis. The follow-up period ranged from 12 to 49 months (mean 31.6 months). Endoscopic procedures were completely successful in all but two patients. In one of the remaining two patients, a repeated endoscopic cystocisternostomy was performed with success because of closure of the previous stoma. In the other, a subcutaneous collection of cerebrospinal fluid (CSF) was managed by insertion of an lumboperitoneal shunt. A subdural collection of CSF developed in three patients; it was treated with insertion of a subduroperitoneal shunt in one patient and managed conservatively in the other two patients, resolving spontaneously without further treatment. Neurodevelopmental evaluation performed in six patients showed normal intelligence (total intelligence quotient [IQ] > 80) in three patients, mild developmental delay (total IQ 50-80) in two, and severe developmental delay (total IQ < 50) in one. Endoscopic treatment of interhemispheric cysts can be considered a useful alternative to traditional treatments, even if some complications are to be expected, such as subdural or subcutaneous CSF collections and CSF leaks due to thinness of cerebral mantle and to the often-associated multifactorial hydrocephalus.

Specific language impairment: linguistic and neurobiological aspects

Specific language impairment (SLI) occurs when children present language maturation, at least 12 months behind their chronological age in the absence of sensory or intellectual deficits, pervasive developmental disorders, evident cerebral damage, and adequate social and emotional conditions. The aim of this study was to classify a group of children according to the subtypes of SLI and to correlate clinical manifestations with cortical abnormalities. Seventeen children with SLI were evaluated. Language assessment was based on standardized test (Peabody) and a non-standardized protocol, which included phonological, syntactical, semantical, pragmatical and lexical aspects of language. All children, except one, had abnormal MRI. Thirteen children presented perisylvian polymicrogyria. The MRI findings in the remaining three patients were: right frontal polymicrogyria, bilateral fronto-parietal atrophy, and hypogenesis of corpus callosum with Chiari I. The data show that patients with posterior cortical involvement tended to present milder form of SLI (no sign of articulatory or bucofacial praxis disturbance), while diffuse polymicrogyric perisylvian cortex usually was seen in patients who presented severe clinical manifestation, mainly phonological-syntactic deficit. In conclusion, SLI may be associated with perisylvian polymicrogyria and clinical manifestation may vary according to the extent of cortical anomaly.

Pituitary duplication associated with oral dermoid and corpus callosum hypogenesis

We report a case of pituitary duplication in a neonate girl whose magnetic resonance (MR) images showed unusual findings of hypogenesis of the corpus callosum and oral dermoid. Pituitary duplication is an extremely rare malformation, with only a few previously reported cases. It occurs most commonly in association with complicated midline and skull base anomalies. We present a case of this malformation with special emphasis on the hypogenesis of splenium of the corpus callosum and oral dermoid.

The molecular basis of Goodpasture and Alport syndromes: beacons for the discovery of the collagen IV family.

<h3>Objective</h3> To provide new insights into the <i>FOXG1-</i>related clinical and imaging phenotypes and refine the phenotype-genotype correlation in <i>FOXG1</i> syndrome. <h3>Methods</h3> We analyzed the clinical and imaging phenotypes of a cohort of 45 patients with a pathogenic or likely pathogenic <i>FOXG1</i> variant and performed phenotype-genotype correlations. <h3>Results</h3> A total of 37 <i>FOXG1</i> different heterozygous mutations were identified, of which 18 are novel. We described a broad spectrum of neurodevelopmental phenotypes, characterized by severe postnatal microcephaly and developmental delay accompanied by a hyperkinetic movement disorder, stereotypes and sleep disorders, and epileptic seizures. Our data highlighted 3 patterns of gyration, including frontal pachygyria in younger patients (26.7%), moderate simplified gyration (24.4%) and mildly simplified or normal gyration (48.9%), corpus callosum hypogenesis mostly in its frontal part, combined with moderate-to-severe myelination delay that improved and normalized with age. Frameshift and nonsense mutations in the N-terminus of <i>FOXG1</i>, which are the most common mutation types, show the most severe clinical features and MRI anomalies. However, patients with recurrent frameshift mutations c.460dupG and c.256dupC had variable clinical and imaging presentations. <h3>Conclusions</h3> These findings have implications for genetic counseling, providing evidence that N-terminal mutations and large deletions lead to more severe <i>FOXG1</i> syndrome, although genotype-phenotype correlations are not necessarily straightforward in recurrent mutations. Together, these analyses support the view that <i>FOXG1</i> syndrome is a specific disorder characterized by frontal pachygyria and delayed myelination in its most severe form and hypogenetic corpus callosum in its milder form.