Child Neurology: KMT2B-Related Dystonia in a Young Child With Worsening Gait Abnormality.

KMT2B gene-related dystonia (DYT-KMT2B) is a primarily childhood-onset movement disorder that usually starts with lower limb dystonia progressing into generalized dystonia. Our patient described in this study experienced difficulty gaining weight, laryngomalacia, and feeding difficulties during infancy and later developed gait difficulties, frequent falls, and toe walking. Gait assessment revealed prominent bilateral intoeing, intermittent ankle inversion, and extension of left leg. At times, the gait seemed to be spastic. Whole-exome sequencing revealed a novel de novo heterozygous likely pathogenic variant, c.7913 T > A (p.V2638E), in the KMT2B gene located in chromosome 19. This variant, which has not been previously published as pathogenic or benign in the literature, can be added to the repertoire of KMT2B variants causing inherited dystonias.

Paediatric Cogan Syndrome masquerading as IgA vasculitis.

Paediatric Cogan Syndrome is a rare and underrecognised autoimmune vasculitis characterised by ocular inflammation and sensorineural hearing loss. Its etiopathogenesis, diagnosis, and management are not well defined. We report a 12-year-old girl who initially presented with symptoms of IgA vasculitis formerly called Henoch Schoenlein Purpura (HSP) and eventually developed anterior uveitis and bilateral sensorineural hearing loss leading to the diagnosis of atypical Cogan Syndrome. The workup for infectious etiologies and other systemic rheumatologic disorders was negative. The management was multidisciplinary involving Rheumatology, Ophthalmology, Otorhinolaryngology, and Audiology. The anterior uveitis responded well to systemic glucocorticoids and Methotrexate, but the hearing loss was grossly progressive warranting a cochlear implant. We are not aware of Paediatric Cogan Syndrome being reported as a mimicker of IgA vasculitis previously in the literature. It is an important finding as IgA vasculitis is prevalent in the paediatric age group and new-onset ocular or vestibular symptoms after IgA vasculitis should alert the clinician to the possibility of Cogan Syndrome. In the absence of well-defined diagnostic criteria, it is crucial to recognise the clinical symptoms of Paediatric Cogan Syndrome for early diagnosis and treatment since the delay in diagnosis can lead to permanent disability.

Case Report: SATB2-Associated Syndrome Overlapping With Clinical Mitochondrial Disease Presentation: Report of Two Cases.

SATB2-associated syndrome (SAS) is an autosomal dominant neurogenetic multisystemic disorder. We describe two individuals with global developmental delay and hypotonia who underwent an extensive evaluation to rule out an underlying mitochondrial disorder before their eventual diagnosis of SAS. Although the strict application of the clinical mitochondrial disease score only led to the designation of "possible" mitochondrial disorder for these two individuals, other documented abnormalities included nonspecific neuroimaging findings on magnetic resonance imaging and magnetic resonance spectroscopy, decreased complex I activity on muscle biopsy for patient 2, and variation in the size and relative proportion of types of muscle fibers in the muscle biopsies that were aligned with mitochondrial diseases. SAS should be in the differential diagnoses of mitochondrial disorders, and broad-spectrum diagnostic tests such as exome sequencing need to be considered early in the evaluation process of undiagnosed neurodevelopmental disorders.