Angelman syndrome with mosaic paternal uniparental disomy suggestive of mitotic nondisjunction.

Angelman syndrome (AS) is caused by the functional absence of the maternal ubiquitin-protein ligase E3A (UBE3A) gene. Approximately 5% of AS is caused by paternal uniparental disomy of chromosome 15 (UPD(15)pat), most of which is considered to result from monosomy rescue. However, little attention has focused on how UPD(15)pat occurs. We suggest the mitotic nondisjunction mechanism as a cause of UPD(15)pat in a six-year-old patient presenting with distinctive characteristics in line with AS. DNA methylation screening of 15q11-q13 showed a paternal band and a faint maternal band, suggestive of mosaic status. By trio-based microsatellite analysis, we confirmed a large proportion of UPD(15)pat cells and a small proportion of cells of biparental origin. Single nucleotide polymorphism (SNP) microarray revealed isodisomy of the entire chromosome 15. These results suggest that the UPD(15)pat of the patient resulted from mitotic nondisjunction, which may also be the cause of other cases of AS with UPD(15)pat.

Ultrasonography of the internal carotid artery during therapeutic hypothermia.

The purpose of this study was to determine the accuracy of mean blood flow velocity (mean V) in the internal carotid artery (ICA) for prediction of outcome in infants with hypoxic-ischemic encephalopathy (HIE) exposed to therapeutic hypothermia (TH). Five newborns with HIE who met the criteria for TH were enrolled. Ultrasonography of the right and left ICA was performed before, during, and after TH. Mean V of the sampling point in each ICA was measured. Mean V was suppressed during TH and increased after rewarming in four infants with normal neurological development. In one infant with neurological disability, however, mean V increased during TH and decreased after therapy. In conclusion, cervical ultrasonography for ICA in infants during TH may be useful for the prediction of neurodevelopmental outcome.

A nationwide survey of Vici syndrome in Japan.

BACKGROUND: Vici syndrome (VICIS) is a congenital disorder characterized by agenesis of the corpus callosum, cataracts, hypopigmentation, cardiomyopathy, combined immunodeficiency, microcephaly, and failure to thrive. This study aimed to elucidate the number of patients with VICIS, its clinical characteristics and relevant genetic information in Japan. METHODS: After developing diagnostic criteria for VICIS, we conducted a nationwide questionnaire-based survey of VICIS in Japan. In the initial survey, we investigated the number of VICIS patients who fulfilled definite or probable criteria. The second survey was used to obtain detailed clinical and genetic information of VICIS from institutions that responded to the initial survey. RESULTS: Clinical information was available for 15 patients (12 definite, three probable). As of October 2023, nine patients (60%) were alive and six (40%) had died. All patients presented with developmental delay, agenesis of the corpus callosum, elevated serum aspartate/alanine aminotransferase, hypopigmentation and hypotonia. Developmental delay was profound. Most patients developed recurrent infection, high-arched palate, epilepsy, failure to thrive, and microcephaly. Cardiomyopathy and cataracts, both initially described as principal features in VICIS, were notably uncommon in our study. Based on the information collected, all 14 patients for whom information was available received home medical care: 11 (79%) received tube feeding, three (21%) required noninvasive ventilation, four (29%) required tracheostomy, and four (29%) required home subcutaneous immunoglobulin administration. CONCLUSION: This study revealed for the first time the nationwide status of patients with VICIS in Japan. The mortality rate of patients with VICIS is as high as 40%, and almost all VICIS patients require various forms of home medical care, necessitating comprehensive management. Additionally, we identified one adult patient, underscoring the need for comprehensive medical management extending into adulthood for patients with VICIS.

Genotype-phenotype correlation over time in Angelman syndrome: Researching 134 patients.

Angelman syndrome (AS) is a severe neurodevelopmental disorder caused by the loss of function of maternal UBE3A. The major cause of AS is a maternal deletion in 15q11.2-q13, and the minor causes are a UBE3A mutation, uniparental disomy (UPD), and imprinting defect (ID). Previous reports suggest that all patients with AS exhibit developmental delay, movement or balance disorders, behavioral characteristics, and speech impairment. In contrast, a substantial number of AS patients with a UBE3A mutation, UPD, or ID were reported not to show these consistent features and to show age-dependent changes in their features. In this study, we investigated 134 patients with AS, including 57 patients with a UBE3A mutation and 48 patients with UPD or ID. Although developmental delay was present in all patients, 20% of patients with AS caused by UPD or ID did not exhibit movement or balance disorders. Differences were also seen in hypopigmentation and seizures, depending on the causes. Moreover, patients with a UBE3A mutation, UPD, or ID tended to show fewer of the specific phenotypes depending on their age. In particular, in patients with UPD or ID, easily provoked laughter and hyperactivity tended to become more pronounced as they aged. Therefore, the clinical features of AS based on cause and age should be understood, and genetic testing should not be limited to patients with the typical clinical features of AS.