Exploring unsolved cases of lissencephaly spectrum: integrating exome and genome sequencing for higher diagnostic yield.

Lissencephaly is a rare brain malformation characterized by abnormal neuronal migration during cortical development. In this study, we performed a comprehensive genetic analysis using next-generation sequencing in 12 unsolved Japanese lissencephaly patients, in whom PAFAH1B1, DCX, TUBA1A, and ARX variants were excluded using the Sanger method. Exome sequencing (ES) was conducted on these 12 patients, identifying pathogenic variants in CEP85L, DYNC1H1, LAMC3, and DCX in four patients. Next, we performed genome sequencing (GS) on eight unsolved patients, and structural variants in PAFAH1B1, including an inversion and microdeletions involving several exons, were detected in three patients. Notably, these microdeletions in PAFAH1B1 could not to be detected by copy number variation (CNV) detection tools based on the depth of coverage methods using ES data. The density of repeat sequences, including Alu sequences or segmental duplications, which increase the susceptibility to structural variations, is very high in some lissencephaly spectrum genes (PAFAH1B1, TUBA1A, DYNC1H1). These missing CNVs were due to the limitations of detecting repeat sequences in ES-based CNV detection tools. Our study suggests that a combined approach integrating ES with GS can contribute to a higher diagnostic yield and a better understanding of the genetic landscape of the lissencephaly spectrum.

Pneumatosis Cystoides Intestinalis in Muscular Dystrophy and Congenital Myopathies: A Report of Five Cases.

Pneumatosis cystoides intestinalis (PCI) is a rare disease wherein air accumulates in the intestinal subserosa and submucosa, causing multiple gaseous cysts within the gastrointestinal wall. While PCI has various known risk factors, reports identifying muscular diseases as a factor are scarce. The aim of this study is to elucidate the clinical characteristics of PCI in muscle disease. We present a case series of five cases, including two cases of Duchenne muscular dystrophy (DMD) and three cases of rare congenital myopathies. All cases are of male patients, with poor intestinal peristalsis and constipation, who underwent tube feeding and mechanical ventilation via tracheostomy. They had no signs of severe complications, such as intestinal necrosis, and all of them improved with conservative treatment. Case 1 is a 23-year-old man with DMD who developed cardiopulmonary arrest at the age of 20 years. Pulmonary hemorrhage occurred three months before the incidental detection of PCI in the ascending colon, which resolved with conservative oxygen treatment. Case 2 is a 25-year-old man with DMD who progressed to immobility necessitating tracheostomy at the age of 20 years. He experienced persistent abdominal pain and nausea, and PCI was detected in the cecum and ascending colon. He showed near-complete resolution of PCI after three months of conservative treatment. Case 3 is a six-year-old boy with reducing body myopathy. Constipation was diagnosed at four years of age. He experienced intermittent bloody stools, leading to the incidental detection of PCI at six years of age. After two months of conservative treatment, the PCI resolved with no subsequent recurrence. Case 4 is a 33-year-old man with infantile severe myotubular myopathy. He required mechanical ventilation immediately after birth and later underwent tracheostomy and tube feeding due to complications. At the age of 27 years, PCI was incidentally detected on abdominal CT. He had episodes of remission and worsening for a few years; however, PCI completely resolved after three years. Case 5 is a 27-year-old man with nemaline myopathy. At the age of 14 years, he had persistent bloody stools. After lower gastrointestinal endoscopy, he was diagnosed with PCI with numerous rectal cysts. PCI required no specific therapeutic intervention. There was spontaneous resolution of PCI and bloody stools. Given that PCI lacks specific symptoms and cases with muscular diseases often experience abdominal issues, many cases are liable to be overlooked or misdiagnosed. Cases with muscular diseases complaining of persistent abdominal symptoms should undergo radiographic imaging to rule out PCI.

Validity of the Functional Classification of the Upper Extremities for Duchenne Muscular Dystrophy.

Objectives: Some upper-limb function assessments can evaluate treatments in the non-ambulatory stage of Duchenne muscular dystrophy (DMD). The Functional Classification of the Upper Extremities (FCUE) was developed for DMD in Japan. The FCUE is easier to use than the Performance of Upper Limb (PUL) and is more detailed than the Brooke Upper Extremity Scale. This study aimed to determine the concurrent validity of FCUE with other methods of assessment for DMD. Methods: This retrospective study reviewed the medical records of 39 boys with DMD from the National Center of Neurology and Psychiatry to evaluate the concurrent validity of the FCUE and PUL using non-parametric Spearman rank correlation (ρ). We also determined the concurrent validity of the Brooke Upper Extremity Scale and PUL for comparison. Results: The ρ value between the FCUE and PUL was -0.914 (P<0.001). The FCUE showed robust concurrent validity with the PUL. That correlation between the FCUE and Brooke Upper Extremity Scale gave a ρ value of -0.854 (P<0.001). Conclusions: The FCUE had a higher concurrent validity with the PUL than with the Brooke Upper Extremity Scale. The FCUE is considered a valid assessment tool of upper-limb function in boys with DMD. Selecting the best assessment method depends on the severity of the patient's condition and a balance between assessment accuracy and evaluation time.

Epidemiological study on pediatric-onset dystonia in Japan: A questionnaire-based survey.

OBJECTIVE: This study aimed to investigate the clinical characteristics of pediatric-onset dystonia in Japan, addressing the diagnostic challenges arising from symptom variations and etiological diversity. METHODS: From 2020 to 2022, questionnaires were distributed to 1218 board certified child neurologists (BCCNs) by Japanese Society of Child Neurology. In the primary survey, participants were asked to report the number of patients with pediatric-onset dystonia under their care. Subsequently, the follow-up secondary survey sought additional information on the clinical characteristics of these patients. RESULTS: The primary survey obtained 550 responses (response rate: 45 %) from BCCNs for their 736 patients with dystonia. The predominant etiologies included inherited cases (with DYT10   being the most prevalent, followed by DYT5 and ATP1A3-related neurologic disorders), acquired cases (with perinatal abnormalities being the most common), and idiopathic cases. The secondary survey provided clinical insights into 308 cases from 82 BCCNs. Infancy-onset dystonia presented as persistent and generalized with diverse symptoms, primarily linked to ATP1A3-related neurologic disorders and other genetic disorders resembling acquired dystonia. Conversely, childhood/adolescent-onset dystonia showed paroxysmal, fluctuating courses, predominantly affecting limbs. The most common etiologies were DYT5 and DYT10 , leading to therapeutic diagnoses. CONCLUSION: Pediatric-onset dystonia in Japan was treated by 28 % of BCCNs. The majority of cases were inherited, with high prevalence rates of DYT5 and DYT10 . Infancy-onset dystonia exhibits diverse etiologies and symptoms, emphasizing the utility of various examinations, including genetic testing. These findings significantly contribute to our understanding of pediatric-onset dystonia in Japan, although this study has the limitation of questionnaire survey.