PURA-Related Neurodevelopmental Disorders with Epilepsy Treated with Ketogenic Diet: A Case-Based Review.

PURA syndrome is a congenital developmental disorder caused by de novo mutations in the PURA gene, which encodes a DNA/RNA-binding protein essential for transcriptional and translational regulation. We present the case of an 11-year-old patient with a de novo frameshift variant in the PURA gene, identified through whole exome sequencing (WES). In addition to the classical PURA deficiency phenotype, our patient exhibited pronounced sialorrhea and seizures, which were effectively treated with the ketogenic diet (KD). Our integrative approach, combining a literature review and bioinformatics data, has led to the first documented clinical case showing improvement in both sialorrhea and seizures with KD treatment, a phenomenon not previously reported. Although a direct relationship between the de novo PURA mutation and the KD was not established, we identified a novel frameshift deletion associated with a new clinical phenotype.

Genome-wide epigenetic signatures facilitated the variant classification of the PURA gene and uncovered the pathomechanism of PURA-related neurodevelopmental disorders.

PURPOSE: Rare genetic variants in the PURA gene cause the PURA-related neurodevelopmental disorder (PURA-NDD), characterized by neonatal abnormalities and developmental delay. Using genome-wide DNA methylation analysis on patients with PURA variants, we aim to establish a PURA-NDD-specific methylation profile and provide further insights on the molecular basis of the PURA-NDD. METHODS: Twenty three individuals (including 12 unpublished) carrying PURA variants were enrolled. We conducted the Illumina Infinium EPIC microarray analysis in 17 PURA-NDD individuals. In vitro experiments were performed to examine how PURA variants affect Pur-a expression. RESULTS: Additional phenotypes in 12 newly identified patients were described in this study. Genome-wide DNA methylation analysis unveiled distinctive methylation profiles to PURA-NDD, and the established classifier can reclassify PURA variants of uncertain significance. Patients bearing PURA hapoloinsufficient and missense variants have comparable DNA methylation profiles, and cells expressing these PURA variants showed consistent Pur-a downregulation, suggesting a haploinsufficiency mechanism. CONCLUSION: Patients with PURA-NDD exhibit a specific episignature, which has potential to aid identification and diagnosis of PURA-NDD patients and offer implications for further functional investigations.

Síndrome PURA en una niña con retraso grave del desarrollo: un diagnóstico desafiante / PURA syndrome in a child with severe developmental delay: a challenging diagnosis

Introducción: El síndrome PURA es una condición autosómica dominante poco común causada por variantes patogénicas de novo en el gen PURA y que se caracteriza por un fenotipo multisistémico que incluye retraso del neurodesarrollo global, hipotonía temprana, ausencia de habla, dificultades para alimentarse, hipersomnolencia, epilepsia y trastornos del movimiento. Caso clínico: Presentamos una niña de 9 años con hipotonía y dificultades para alimentarse con retraso del crecimiento desde el período neonatal. A la edad de 3 años era evidente el retraso motor e intelectual, tenía una marcha de base amplia, no hablaba y una respuesta de sobresalto acústico exagerada. Desarrolló estereotipias de mano-boca y epilepsia a los 6 años. La monitorización electroencefalográfica continua de 24 horas reveló una actividad lenta global y una actividad epileptiforme frecuente en las áreas temporal izquierda y centrotemporal. La resonancia magnética del cerebro reveló un retraso en la mielinización. A los 6 años, la secuenciación clínica del exoma identificó una variante patógena heterocigótica en el gen PURA, c.153delA p. (Leu54CysfsTer24). Conclusión: El síndrome PURA tiene características clínicas similares a otros trastornos neurológicos, pero la asociación con algunas características clínicas, no tan comunes en otras entidades neurológicas, como no poder hablar, pero poder seguir órdenes simples, y una respuesta de sobresalto acústico exagerado, deben ser factores de sospecha de síndrome PURA y servir para realizar un análisis genético para confirmar el diagnóstico y proporcionar una intervención multidisciplinar precoz.(AU)

Introduction: PURA syndrome is a rare autosomal dominant condition caused by de novo pathogenic variants in PURA gene and characterized by a multisystemic phenotype that includes global neurodevelopmental delay, early hypotonia, absence of speech, feeding difficulties, hypersomnolence, epilepsy and movement disorders. Case report: We report a 9-year-old girl with hypotonia and feeding difficulties with failure to thrive since the neonatal period. At the age of 3 years motor and intellectual delay were evident, she had a wide-based gait, no speech and an exaggerated acoustic startle response. She developed hand-mouthing stereotypies and epilepsy at 6 years old. The 24 hours continuous electroencephalogram monitoring revealed global slow activity and frequent epileptiform activity in left temporal and centrotemporal areas. The brain MRI revealed delayed myelination. At 6 years old the clinical exome sequencing identified a heterozygous pathogenic variant in the PURA gene, c.153delA p.(Leu54CysfsTer24). Conclusion: PURA syndrome has clinical features similar to other neurological disorders but the association with some clinical features, not as common in other neurological entities, like never being able to speak but being able to follow simple orders and exaggerated acoustic startle response, should raise the suspicion of PURA syndrome and genetic analysis must be performed to confirm the diagnosis and provide early multidisciplinary intervention.(AU)

Early-onset bradykinetic rigid syndrome and reflex seizures in a child with PURA syndrome.

PURA syndrome is a distinct form of developmental encephalopathy, characterized by early-onset hypotonia, severe developmental delay, intellectual disability, epilepsy and respiratory and gastrointestinal disorders. We report a child with PURA syndrome, harbouring a previously described mutation, whose phenotype included two peculiar aspects: (1) hypokinetic-rigid syndrome, which was part of the clinical presentation from an early stage of the disease, and (2) reflex seizures, consisting of a series of spasms. We provide detailed clinical description and video recordings demonstrating both these aspects that are newly described in PURA syndrome. The early clinical features described here may therefore be included in the complex phenotype associated with PURA gene mutations and may help in the early diagnosis of patients. Furthermore, PURA syndrome should be considered in the differential diagnosis of early-onset bradykinetic rigid syndromes.

Long-term follow-up of a patient with 5q31.3 microdeletion syndrome and the smallest de novo 5q31.2q31.3 deletion involving PURA.

BACKGROUND: Purine-rich element binding protein A (PURA, MIM 600473), is considered the crucial phenocritical gene for an emerging 5q31.3 microdeletion syndrome. To date, at least seven affected individuals with overlapping 5q31.2q31.3 deletions, varying in size from 2.6 to 5 Mb, have been reported sharing neurologic features such as severe developmental delay, neonatal hypotonia, early feeding difficulties, respiratory distress and EEG abnormalities. The recent finding that de novo PURA point mutations are indeed sufficient to cause the severe neurological symptoms also observed in patients with 5q31.2q31.3 deletion further reinforces the gene's causative role in 5q31.3 microdeletion syndrome. CASE PRESENTATION: The present patient, aged 26 years, is the oldest reported individual and carries the smallest de novo 5q31.2q31.3 microdeletion encompassing PURA (360 kb). Her clinical history summarizes the mainly neurodevelopmental phenotype described in children with 5q31.3 microdeletion syndrome. In addition, our patient exhibited a remarkable deterioration of clinical symptoms, starting at the beginning of adolescence, pubertal delay and primary amenorrhea. While epileptic seizures were successfully treated during her life, feeding problems showed a poor outcome, her respiratory problems increased and eventually became severe enough to cause her death. CONCLUSION: The clinical and molecular findings reported here provide further evidence that 5q31.3 microdeletion syndrome is a clinically discernible PURA-related disorder and describe the previously unreported natural evolution of the disease in a 26 years old patient.

Expression of PURA gene and its protein in nephridial tissue of rats with fluorosis of coal-burning / 中国地方病学杂志

Objective To investigate the meaning of PURA gene and its protein in nephridial tissue of the rats with endemic fluorosis of coal burning. Methods Thirty-six SD rats of 80 - 100 g, body weight were randomly divided into control group, low fluorosis group and high fluorosis group according to body weight, 12 in each group, the number of female and male in each group was the same respectively. The control group, Low fluorosis group and high fluorosis group rots were fed with 1.5,25.0,60.0 mg/kg fluoride content in feedstuff, to establish the animal model of fluorosis. Expressions of both mRNA and its protein of PURA gene in rat nephridium tissue, were determined by RT-PCR and immunohistochemistry after four-month experimental period. Results The expressions of PURA mRNA[(2.74± 1.06),(4.29 ± 2.11)] and its protein[ (28 827.91 ± 4801.94),(61 146.96 ± 4997.55)] in low fluorosis group and high fluorosis group was higher than that in the control group[ ( 1.13 ± 0.87), (7131.95 ± 1524.54), all P < 0.05]. And the expressions of PURA mRNA and protein in high fluorosis groups was higher than that in low fluorosis greup(all P < 0.05). Conclusion High fluoride can lead to the high expression of PURA gene mRNA and protein in the rat nephridium tissue exposed to sodium fluoride.