Jong Hee Chae

BACKGROUND: Neuromuscular disorders are a clinically, pathologically, and genetically heterogeneous group. Even for the experienced clinician, an accurate diagnosis is often challenging due to the complexity of these disorders. Here, we investigated the utility of next generation sequencing (NGS) in early diagnostic algorithms to improve the diagnosis for patients currently lacking precise molecular characterisation, particularly for hereditary myopathies. METHODS: 43 patients presenting with ea

Leigh syndrome (LS), the most common childhood mitochondrial disorder, has characteristic clinical and neuroradiologic features. Mutations in more than 75 genes have been identified in both the mitochondrial and nuclear genome, implicating a high degree of genetic heterogeneity in LS. To profile these genetic signatures and understand the pathophysiology of LS, we recruited 64 patients from 62 families who were clinically diagnosed with LS at Seoul National University Children's Hospital. Mitoch

BACKGROUND: Duchenne muscular dystrophy or Becker muscular dystrophy might be a suitable candidate disease for application of next-generation sequencing in the genetic diagnosis because the complex mutational spectrum and the large size of the dystrophin gene require two or more analytical methods and have a high cost. The authors tested whether large deletions/duplications or small mutations, such as point mutations or short insertions/deletions of the dystrophin gene, could be predicted accura

OBJECTIVE: Rett syndrome (RTT) and epileptic encephalopathy (EE) are devastating neurodevelopmental disorders with distinct diagnostic criteria. However, highly heterogeneous and overlapping clinical features often allocate patients into the boundary of the two conditions, complicating accurate diagnosis and appropriate medical interventions. Therefore, we investigated the specific molecular mechanism that allows an understanding of the pathogenesis and relationship of these two conditions. METH

The cerebellum is known to have an inhibitory effect on seizures. Nevertheless, cerebellar dysplastic lesions can be epileptogenic. A 4-month-old infant had paroxysmal facial contractions; tachypnea and nystagmoid eyeball and tremulous movements were occasionally combined. These evolved to stereotypic clinical patterns and frequencies, which increased despite administration of antiepileptic drugs (AEDs). Magnetic resonance imaging (MRI) demonstrated a mass arising from the superior cerebellar pe

For the noninvasive prenatal diagnosis (NIPD) of X-linked recessive diseases such as Duchenne muscular dystrophy (DMD), maternal haplotype phasing is a critical step for dosage analysis of the inherited allele. Until recently, the proband-based indirect haplotyping method has been preferred despite its limitations for use in clinical practice. Here, we describe a method for directly determining the maternal haplotype without requiring the proband's DNA in DMD families. We used targeted linked-re

BACKGROUND: Noninvasive prenatal diagnosis of monogenic disorders using maternal plasma and targeted massively parallel sequencing is being investigated actively. We previously demonstrated that comprehensive genetic diagnosis of a Duchenne muscular dystrophy (DMD) patient is feasible using a single targeted sequencing platform. Here we demonstrate the applicability of this approach to carrier detection and noninvasive prenatal diagnosis. METHODS: Custom solution-based target enrichment was desi

There have been a few reports of GM3 synthase deficiency since the disease of the ganglioside biosynthetic pathway was first reported in 2004. It is characterized by infantile-onset epilepsy with severe intellectual disability, blindness, cutaneous dyspigmentation, and choreoathetosis. Here we report the cases of two Korean female siblings with ST3GAL5 variants, who presented with a Rett-like phenotype. They had delayed speech, hand stereotypies with a loss of purposeful hand movements, and chor

Muscular dystrophy (MD) is a genetically and clinically heterogeneous group of disorders. Here, we performed targeted sequencing of 18 limb-girdle MD (LGMD)-related genes in 35 patients who were highly suspected of having MD. We identified one or more pathogenic variants in 23 of 35 patients (65.7%), and a genetic diagnosis was performed in 20 patients (57.1%). LGMD2B was the most common LGMD type, followed by LGMD1B, LGMD2A, and LGMD2G. Among the three major LGMD types in this group, LGMD1B was

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the mutation status of PANK2 among Korean patients with pantothenate kinase-associated neurodegeneration (PKAN) and to document the outcome of pallidal deep brain stimulation (DBS). METHODS: Direct sequencing and deletion/duplication analysis of PANK2 were conducted in 12 patients (11 unrelated) with PKAN, diagnosed on the basis of extrapyramidal dysfunction and the 'eye-of-the-tiger sign' on brain magnetic resonance imaging (MRI)