Lissencephaly in Shih Tzu dogs.

BACKGROUND: Lissencephaly is a brain malformation characterized by smooth and thickened cerebral surface, which may result in structural epilepsy. Lissencephaly is not common in veterinary medicine. Here, we characterize the first cases of lissencephaly in four Shih Tzu dogs, including clinical presentations and findings of magnetic resonance imaging of lissencephaly and several concomitant brain malformations. CASE PRESENTATION: Early-onset acute signs of forebrain abnormalities were observed in all dogs, which were mainly cluster seizures and behavioral alterations. Based on neurological examination, the findings were consistent with symmetrical and bilateral forebrain lesions. Metabolic disorders and inflammatory diseases were excluded. Magnetic resonance imaging for three dogs showed diffuse neocortical agyria and thickened gray matter while one dog had mixed agyria and pachygyria. Other features, such as internal hydrocephalus, supracollicular fluid accumulation, and corpus callosum hypoplasia, were detected concomitantly. Antiepileptic drugs effectively controlled cluster seizures, however, sporadic isolated seizures and signs of forebrain abnormalities, such as behavioral alterations, central blindness, and strabismus persisted. CONCLUSIONS: Lissencephaly should be considered an important differential diagnosis in Shih Tzu dogs presenting with early-onset signs of forebrain abnormalities, including cluster seizures and behavioral alterations. Magnetic resonance imaging was appropriate for ante-mortem diagnosis of lissencephaly and associated cerebral anomalies.

Lissencephaly in a Pekingese.

A 1-year-old neutered male Pekingese was presented for evaluation and further treatment of cluster seizures. The dog had behavioral abnormalities, and a prosencephalic lesion was suspected following neurological examination. The dog showed signs of learning difficulty. Magnetic resonance imaging of the brain revealed a remarkably smooth cerebral cortex with a reduced number of gyri, as well as a cystic lesion associated with the quadrigeminal cistern. A diagnosis of lissencephaly, concurrent with a quadrigeminal cisternal cyst, was made. High-dose and multiple anticonvulsants were necessary to control the seizures. This is the first report of lissencephaly in a Pekingese.

Acute myeloid leukemia in Baraitser-Winter cerebrofrontofacial syndrome.

Baraitser-Winter malformation syndrome (BWMS), Fryns-Aftimos syndrome (FA), and craniofrontofacial syndromes (CFFs) have all been recently proposed to be part of the same phenotypic spectrum of Baraitser-Winter cerebrofrontofacial syndrome (BWCFF), which is characterized by facial dysmorphism, ocular coloboma, brain malformations, and intellectual disabilities. In addition to that, the recent discovery of missense mutations in one of the two ubiquitously expressed cytoplasmic ß- and γ-acting-encoding genes ACTB (7p22.1) and ACTG1 (17q25.3) in patients carrying a clinical diagnosis of BWSM, FA, or CCF has provided further evidence that these clinical conditions do indeed belong to the same entity at the molecular level. Two cases of BWCFF patients presenting with malignancies (i.e., acute lymphocytic leukemia and cutaneous lymphoma) have been published thus far. Here, we report a 21-year-old female with molecularly confirmed FA, who developed acute myeloid leukemia (AML). The present finding may indicate that actinopathies could be cancer-predisposing syndromes although small numbers and publication bias should be taken into account. © 2016 Wiley Periodicals, Inc.

The wide spectrum of tubulinopathies: what are the key features for the diagnosis?

Complex cortical malformations associated with mutations in tubulin genes: TUBA1A, TUBA8, TUBB2B, TUBB3, TUBB5 and TUBG1 commonly referred to as tubulinopathies, are a heterogeneous group of conditions with a wide spectrum of clinical severity. Among the 106 patients selected as having complex cortical malformations, 45 were found to carry mutations in TUBA1A (42.5%), 18 in TUBB2B (16.9%), 11 in TUBB3 (10.4%), three in TUBB5 (2.8%), and three in TUBG1 (2.8%). No mutations were identified in TUBA8. Systematic review of patients' neuroimaging and neuropathological data allowed us to distinguish at least five cortical malformation syndromes: (i) microlissencephaly (n = 12); (ii) lissencephaly (n = 19); (iii) central pachygyria and polymicrogyria-like cortical dysplasia (n = 24); (iv) generalized polymicrogyria-like cortical dysplasia (n = 6); and (v) a 'simplified' gyral pattern with area of focal polymicrogyria (n = 19). Dysmorphic basal ganglia are the hallmark of tubulinopathies (found in 75% of cases) and are present in 100% of central pachygyria and polymicrogyria-like cortical dysplasia and simplified gyral malformation syndromes. Tubulinopathies are also characterized by a high prevalence of corpus callosum agenesis (32/80; 40%), and mild to severe cerebellar hypoplasia and dysplasia (63/80; 78.7%). Foetal cases (n = 25) represent the severe end of the spectrum and show specific abnormalities that provide insights into the underlying pathophysiology. The overall complexity of tubulinopathies reflects the pleiotropic effects of tubulins and their specific spatio-temporal profiles of expression. In line with previous reports, this large cohort further clarifies overlapping phenotypes between tubulinopathies and although current structural data do not allow prediction of mutation-related phenotypes, within each mutated gene there is an associated predominant pattern of cortical dysgenesis allowing some phenotype-genotype correlation. The core phenotype of TUBA1A and TUBG1 tubulinopathies are lissencephalies and microlissencephalies, whereas TUBB2B tubulinopathies show in the majority, centrally predominant polymicrogyria-like cortical dysplasia. By contrast, TUBB3 and TUBB5 mutations cause milder malformations with focal or multifocal polymicrogyria-like cortical dysplasia with abnormal and simplified gyral pattern.

Overlapping cortical malformations and mutations in TUBB2B and TUBA1A.

Polymicrogyria and lissencephaly are causally heterogeneous disorders of cortical brain development, with distinct neuropathological and neuroimaging patterns. They can be associated with additional structural cerebral anomalies, and recurrent phenotypic patterns have led to identification of recognizable syndromes. The lissencephalies are usually single-gene disorders affecting neuronal migration during cerebral cortical development. Polymicrogyria has been associated with genetic and environmental causes and is considered a malformation secondary to abnormal post-migrational development. However, the aetiology in many individuals with these cortical malformations is still unknown. During the past few years, mutations in a number of neuron-specific α- and ß-tubulin genes have been identified in both lissencephaly and polymicrogyria, usually associated with additional cerebral anomalies including callosal hypoplasia or agenesis, abnormal basal ganglia and cerebellar hypoplasia. The tubulin proteins form heterodimers that incorporate into microtubules, cytoskeletal structures essential for cell motility and function. In this study, we sequenced the TUBB2B and TUBA1A coding regions in 47 patients with a diagnosis of polymicrogyria and five with an atypical lissencephaly on neuroimaging. We identified four ß-tubulin and two α-tubulin mutations in patients with a spectrum of cortical and extra-cortical anomalies. Dysmorphic basal ganglia with an abnormal internal capsule were the most consistent feature. One of the patients with a TUBB2B mutation had a lissencephalic phenotype, similar to that previously associated with a TUBA1A mutation. The remainder had a polymicrogyria-like cortical dysplasia, but the grey matter malformation was not typical of that seen in 'classical' polymicrogyria. We propose that the cortical malformations associated with these genes represent a recognizable tubulinopathy-associated spectrum that ranges from lissencephalic to polymicrogyric cortical dysplasias, suggesting shared pathogenic mechanisms in terms of microtubular function and interaction with microtubule-associated proteins.

Congenital accessory palpebral aperture--an addition to the spectrum of Delleman syndrome.

Delleman syndrome (oculocerebrocutaneous syndrome, MIM 164180) is characterized by orbital cysts, microphthalmia/anophthalmia, focal skin defects, skin appendages and multiple cerebral malformations. We herein describe a case of an 8-month-old male child with features suggestive of Delleman syndrome along with a rare congenital lid anomaly - an accessory palpebral aperture, not reported so far to the best of our knowledge.

Avaliação de linguagem em um caso de associação entre surdez e paquigiria / Language evaluation in a case of association between deafness and pachygyria

Para que ocorra a aquisição e o desenvolvimento da linguagem é necessária a associação de uma série de fatores, cujo funcionamento harmonioso determina o sucesso desse processo. O comprometimento auditivo pode ser um obstáculo, mas, mesmo assim, a criança surda será capaz de adquirir linguagem por meio de uma língua de sinais. Porém, quando a criança apresenta alterações neurológicas, o acompanhamento fonoaudiológico se faz necessário. Esta pesquisa é um estudo de caso sobre uma criança surda, com idade de 5 anos e 10 meses, em processo de aquisição da língua de sinais, com comprometimento neurológico. Tem como objetivo avaliar, analisar e aprofundar conhecimentos sobre uma doença rara (paquigiria), associada com surdez, mostrando os impactos que isso pode acarretar à criança, em relação à comunicação. A coleta de dados foi efetuada por meio de avaliações formais e observacionais sobre habilidade e modalidade de comunicação utilizada, desenvolvimento linguístico, fonologia e conhecimento lexical na Língua Brasileira de Sinais (LIBRAS), além da aplicação de um questionário. Os resultados apontaram atraso no processo de aquisição de linguagem, mesmo considerando-se a defasagem entre o nascimento da criança e o início da aquisição da LIBRAS, aspectos que podem estar relacionados com o diagnóstico de paquigiria. É importante que o fonoaudiólogo conheça a LIBRAS e saiba avaliar a linguagem da criança utente dessa língua, pois casos como estes revelam a complexidade da associação entre surdez e quadros neurológicos variados.

In order for the acquisition and development of language to occur, it is necessary to associate a number of factors, whose harmonious functioning determines the success of this process. The hearing loss may be an obstacle, but even so, the deaf child will be able to acquire language through a sign language. However, when the child shows neurological changes, the speech monitoring becomes necessary. This research is a case study of a deaf child, aged 5 years and 10 months, in the acquisition of sign language, who presents neurological impairment. It aims to assess, analyze, and deepen the knowledge on a rare disease (pachygyria) associated with deafness, showing the impact that this can pose to the child regarding communication. Data collection was done through formal evaluations and observational regarding the ability and modality used for communication, language development, phonological and lexical knowledge in Brazilian Sign Language (LIBRAS); in addition to a questionnaire. The results showed delay in language acquisition, even considering the gap between the child’s birth and the early acquisition of LIBRAS, aspects that may be related to the diagnosis of pachygyria. It is important that the audiologist know LIBRAS and know to assess the language of the child who uses this language, because cases like these reveal the complexity of the association between deafness and various neurological disorders.

Novel proximal 14q deletion: clinical and diffusion tensor imaging tractography findings in a patient with lissencephaly, agenesis of the corpus callosum, and septo-optic dysplasia.

We report the unique CNS findings in a patient with a proximal chromosome 14q interstitial deletion. Conventional MR imaging allowed the clear delineation of agenesis of the corpus callosum, SOD, and diffuse lissencephaly. DTI tractography played a significant role in the evaluation of the proximal 14q deletion-associated abnormalities, delineating the extent of the dysmorphic connections of the Probst bundles and clarifying that apparent areas of heterotopias were the corticospinal tracts.

Clinical and MRI findings of lissencephaly in a mixed breed dog.

A 7-year-old castrated male mixed-breed dog was presented with a complaint of acute pain. The dog had suffered from isolated seizures for two years. Magnetic resonance imaging (MRI) of the brain revealed a smooth brain surface due to lack of gyri and sulci formation of the cerebrum and thick cortical grey matter. Additionally, ventriculomegaly and an arachnoid cyst were noted. Multiple spinal cord compressions induced by intervertebral disc protrusion were observed on a cervical MRI. Based on these findings, the dog was diagnosed as having lissencephaly concurrent with intervertebral cervical disease. After therapy for seizure and cervical pain, the clinical signs were completely resolved. To the author's knowledge, this is the case report to diagnose lissencephaly in a mixed-breed dog.

Mutations in WDR62, encoding a centrosomal and nuclear protein, in Indian primary microcephaly families with cortical malformations.

Primary microcephaly is an autosomal recessive disorder characterized by smaller than normal brain size and mental retardation. It is genetically heterogeneous with seven loci: MCPH1-MCPH7. We have previously reported genetic analysis of 35 families, including the identification of the MCPH7 gene STIL. Of the 35 families, three families showed linkage to the MCPH2 locus. Recent whole-exome sequencing studies have shown that the WDR62 gene, located in the MCPH2 candidate region, is mutated in patients with severe brain malformations. We therefore sequenced the WDR62 gene in our MCPH2 families and identified two novel homozygous protein truncating mutations in two families. Affected individuals in the two families had pachygyria, microlissencephaly, band heterotopias, gyral thickening, and dysplastic cortex. Using immunofluorescence study, we showed that, as with other MCPH proteins, WDR62 localizes to centrosomes in A549, HepG2, and HaCaT cells. In addition, WDR62 was also localized to nucleoli. Bioinformatics analysis predicted two overlapping nuclear localization signals and multiple WD-40 repeats in WDR62. Two other groups have also recently identified WDR62 mutations in MCPH2 families. Our results therefore add further evidence that WDR62 is the MCPH2 gene. The present findings will be helpful in genetic diagnosis of patients linked to the MCPH2 locus.

[Analysis of the clinical manifestations and magnetic resonance imaging features of 11 patients with lissencephaly].

OBJECTIVE: To analyze the clinical manifestations and magnetic resonance imaging (MRI) features of lissencephaly of various types and provide clinical and imaging evidences for the clinical diagnosis of the disease. METHODS: The clinical symptoms and signs and the findings in neurobehavioral evaluation, laboratory examination and magnetic resonance imaging (MRI) of 11 cases of lissencephaly were investigated retrospectively. RESULTS: The 11 patients consisted of 4 with isolated lissencephaly sequence, 3 with Miller-Dieker syndrome, 3 with cobblestone lissencephaly, and 1 with lissencephaly with cerebellar hypoplasia. The main clinical manifestations included mental retardation, developmental delay, microcephaly, epilepsy, hearing abnormality and facial malformation. Cobblestone lissencephaly presented with congenital muscular dystrophy and eye malformation, and lissencephaly with cerebellar hypoplasia showed ataxia manifestations. In terms of MRI features, classical lissencephaly displayed absent or broad cerebral gyri, thickened cortex and reduced white matter, smooth border between the gray and white matter, and thin white matter. Cobblestone lissencephaly displayed thick cortex and gyri deficiency with cobblestone surface. Lissencephaly with cerebellar hypoplasia presented with pachygyria, cerebellar hypoplasia and hippocampal dysplasia. CONCLUSION: Lissencephaly is a developmental malformation of the brain with obvious heterogeneity, and the clinical manifestations and MRI features can be the evidences for a clinical diagnosis and classification of the disease.

A newborn with congenital complete atrioventricular block, lissencephaly, and skeletal abnormalities: a case of suspected cytomegalovirus infection.

We present a case of congenital complete atrioventricular block in a preterm microcephalic male with multiple additional congenital anomalies, including spinal and rib abnormalities. The heart was structurally normal, and maternal tests for autoimmune disorders were negative. The brain had an immature lissencephalic appearance, suggestive of an insult early in gestation. Genetic testing was normal, virtually excluding chromosomal disorders that are known to cause lissencephaly. Viral studies were suggestive of cytomegalovirus infection during early gestation, and we believe that the patient's clinical presentation was most likely the result of an early cytomegalovirus infection. The finding of complete atrioventricular block in a patient with presumed cytomegalovirus infection would represent a very rare complication. "Isolated" complete atrioventricular block in a fetus should be considered an incentive for an extensive work-up in search for a possible etiology, rather than accepted as a final diagnosis.

[Developmental malformations of the cerebral cortex]. / Heterotopie, Polymikrogyrie, Lissenzephalie und Co - Malformationen der kortikalen Hirnentwicklung.

Migration disorders (MD) are increasingly recognized as an important cause of epilepsy and developmental delay. Up to 25 % of children with refractory epilepsy have a cortical malformation. MD encompass a wide spectrum with underlying genetic etiologies and clinical manifestations. Research regarding the delineation of the genetic and molecular basis of these disorders has provided greater insight into the pathogenesis of not only the malformation but also the process involved in normal cortical development. Diagnosis of MD is important since patients who fail three antiepileptic medications are less likely to have their seizures controlled with additional trials of medications and therefore epilepsy surgery should be considered. Recent improvements in neuroimaging have resulted in a significant increase in the recognition of MD. Findings can be subdivided in disorders due to abnormal neurogenesis, neuronal migration, neuronal migration arrest and neuronal organization resulting in different malformations like microcephaly, lissencephaly, schizencephaly and heterotopia. The examination protocol should include T 1-w and T 2-w sequences in adequate slice orientation. T 1-w turbo-inversion recovery sequences (TIR) can be helpful to diagnose heterotopia. Contrast agent is needed only to exclude other differential diagnoses.

The treatment of cerebral salt wasting with fludrocortisone in a child with lissencephaly.

Hyponatremia is the most frequent electrolyte disorder in critically ill neurological patients. The major differential diagnoses in this situation are the syndrome of inappropriate antidiuretic hormone secretion, marked by inappropriate retention of free water, and cerebral salt wasting, characterized by excessive urinary loss of sodium and resulting in polyuria and extracellular volume contraction. Cerebral salt wasting is a syndrome of hyponatremia due to increased urine output and excessive natriuresis described in patients with central nervous system disease. Although cerebral salt wasting has been well described in neurosurgical patients, data regarding pediatric patients is sparse. We present a 34-month-old boy with lissencephaly who developed cerebral salt wasting after brain biopsy. The patient was treated with hypertonic saline and multiple antiepileptic drugs. Fludrocortisone supplementation effectively treated cerebral salt wasting.

Large congenital melanocytic nevi presenting with lissencephaly with an absent corpus callosum.

A neonatal case of provisional neurocutaneous melanosis presenting with lissencephaly is reported. Several congenital nevi were observed on the trunk and extremities of the infant, including a giant congenital hairy nevus over the skull. Brain magnetic resonance imaging revealed a marked ventricular dilatation with pachygyria and an absent corpus callosum; however, an injection of gadolinium did not demonstrate any enhanced lesions. Histopathological investigations by a brain biopsy showed a disorganized and anomalous embryonic cerebral architecture, suggesting lissencephaly. The detailed mechanism of this combined pathology is difficult to explain; however, a developmental disturbance was suggested to be present in both the neural crest cells and the neuroepithelial cells, resulting in the development of neurocutaneous melanosis accompanied with lissencephaly.