Generalized epilepsy in a patient with mosaic Turner syndrome: a case report

Disorders of the eye, ear, skin, and nervous system in women with Turner syndrome -a nationwide cohort study

The literature about eye, ear, nose, skin, and nervous system disorders in women with Turner syndrome is equivocal. Impaired vision and hearing in women with Turner syndrome have been described, and case reports of Turner syndrome girls suffering from epilepsy have been published, but no large population-based-studies have explored the occurrence of any of these disorders. We aimed to investigate the risk of admission with disorders related to the eye, ear, nose, skin, and nervous system, compared with background females, and the impact of hormone replacement therapy on these conditions. 1,156 females with TS diagnosed during 1960-2014 were identified using the Danish Cytogenetic Central Registry and linked with personal-level data from the National Patient Registry and the Medication Statistics Registry. Statistics Denmark randomly identified 115,577 age-matched background females. Negative binomial regression was used to analyze hospital discharge diagnoses, reporting incidence rate ratios (IRR). Women with Turner syndrome have an increased risk of developing eye disorders (IRR 4.3 (95% CI 3.5-5.4), including cataract, glaucoma, ocular movement, and accommodation. The risk of ear disorders (IRR 35.0 (27.9-43.9)) and nose (IRR 2.2 (1.4-3.6)) was increased in women with Turner syndrome, due to otitis media, cholesteatoma, and hearing loss. Disorders of the nervous system such as epilepsy were increased IRR 6.2 (2.4-15.9), along with skin conditions IRR 2.2 (95%CI 1.7-2.7) like psoriasis, atopic dermatitis, and ingrown nails.

The Transcription Factor Shox2 Shapes Neuron Firing Properties and Suppresses Seizures by Regulation of Key Ion Channels in Thalamocortical Neurons

Thalamocortical neurons (TCNs) play a critical role in the maintenance of thalamocortical oscillations, dysregulation of which can result in certain types of seizures. Precise control over firing rates of TCNs is foundational to these oscillations, yet the transcriptional mechanisms that constrain these firing rates remain elusive. We hypothesized that Shox2 is a transcriptional regulator of ion channels important for TCN function and that loss of Shox2 alters firing frequency and activity, ultimately perturbing thalamocortical oscillations into an epilepsy-prone state. In this study, we used RNA sequencing and quantitative PCR of control and Shox2 knockout mice to determine Shox2-affected genes and revealed a network of ion channel genes important for neuronal firing properties. Protein regulation was confirmed by Western blotting, and electrophysiological recordings showed that Shox2 KO impacted the firing properties of a subpopulation of TCNs. Computational modeling showed that disruption of these conductances in a manner similar to Shox2's effects modulated frequency of oscillations and could convert sleep spindles to near spike and wave activity, which are a hallmark for absence epilepsy. Finally, Shox2 KO mice were more susceptible to pilocarpine-induced seizures. Overall, these results reveal Shox2 as a transcription factor important for TCN function in adult mouse thalamus.

Turner Syndrome Associated With Refractory Seizures and Intellectual Disability: A Case Study

Turner syndrome (TS) is the most frequent sex abnormality in women. The physical features include short stature, webbing of the neck, and gonadal dysgenesis. Typically, patients with Turner syndrome exhibit no intellectual disability, and a few cases of TS have been associated with epilepsy. Herein, we present a case of TS with intractable epilepsy. The patient presented with global developmental delay at the age of two and karyotyping revealed mosaicism [45, X/46, X del (X) (q21.1)]. At the age of seven, she had generalized tonic epilepsy as well as several focal-onset seizures. She developed daily seizures, which were refractory to several antiepileptic drugs. Interictal electroencephalography (EEG) revealed multifocal spikes, and ictal EEG revealed shifting foci. She visited our hospital at the age of 13. Her peripheral white blood cells G-band and fluorescence in situ hybridization (FISH) method chromosome with cheek swab examinations revealed 45, X. Her peripheral white blood cell mosaic pattern may have disappeared over time or become indetectable. We treated her with clobazam, and then lamotrigine and valproic acid combination therapy, which resulted in a reduction in the frequency of seizures by approximately 50%. Epilepsy and intellectual disability in this case may be due to the mosaic deletion at Xq21.1. Further analysis of similar cases may provide valuable information for effective therapeutic strategies.

Chiari I Malformation Associated with Turner Syndrome

Turner syndrome (TS) is a rare genetic disease due to the absence of one X chromosome. Patients with TS have more subtle neurological/neuropsychiatric problems, while headache is an uncommon clinical presentation which needs attention. We report a 12-year-old child presenting with typical cough headache. Her magnetic resonance imaging revealed Chiari I malformation associated with TS. To the best of our knowledge, Chiari I malformation associated with TS is not described in literature. We report the first case of TS associated with Chiari I malformation. Interestingly, Chiari I malformation is also associated with Noonan's syndrome, which is a close morphological mimicker of TS, raising the possibility of sharing similar pathogenesis in both conditions.

A unique mosaic Turner syndrome patient with androgen receptor gene derived marker chromosome

Patients with Turner syndrome are generally characterized by having short stature with no secondary sexual characteristics. Some abnormalities, such as webbed neck, renal malformations (>50%) and cardiac defects (10%) are less common. The intelligence of these patients is considered normal. Non-mosaic monosomy X is observed in approximately 45% of postnatal patients with Turner syndrome and the rest of the patients have structural abnormalities or mosaicism involving 46,X,i(Xq), 45,X/46,XX, 45,X and other variants. The phenotype of 45,X/46,X,+mar individuals varies by the genetic continent and degree of the mosaicism. The gene content of the marker chromosome is the most important when correlating the phenotype with the genotype. Here we present an 11-year-old female who was referred for evaluation of her short stature and learning disabilities. Conventional cytogenetic investigation showed a mosaic 45,X/46,X,+mar karyotype. Fluorescence in situ hybridization showed that the marker chromosome originated from the X chromosome within the androgen receptor (AR) and X-inactive specific transcript (XIST) genes. Therefore, it is possible that aberrant activation of the marker chromosome, compromising the AR and XIST genes, may modify the Turner syndrome phenotype.