Inherited SCN1A missense mutation in a Dravet Syndrome family: Neuropathological correlation, family screening and implications for adult carriers

INTRODUCTION

Neuropathological findings in Dravet Syndrome (DS) are scarce, especially in adult patients, and often do not have a genetic confirmation. Additionally, the missense SCN1A pathogenic variant found has only been described as de novo mutation in previous literature.

METHODS

We describe the clinical and genetic findings of a family (including three sisters and his father), using Sanger sequencing in the three sisters and in postmortem brain tissue in the father. The present study also shows the neuropathological findings of the father.

RESULTS

Despite the presence of long term drug resistant epilepsy, starting with febrile seizures between 6 and 12 months of age, and intellectual disability (ID), the three sisters were diagnosed with DS in adulthood, identifying a missense SCN1A pathogenic variant in exon 20, previously described as de novo -p.Gly1332Glu (c .3995 G>A). The oldest sister had the most severe phenotype, with severe ID and wheel chair dependency, passing away at 52. The other two sisters had a moderate phenotype, being at the present seizure free, but with significant comorbidities, such as crouch gait and parkinsonism. Several relatives from the paternal path (including the father) presented epilepsy, but without ID. The father was diagnosed with Alzheimer´s Disease (AD) at 60, and because he donated his brain, the same variant was confirmed in postmortem study. Neither the MRI nor the histopathology showed specific morphological changes for DS, consistent with previous studies.

CONCLUSIONS

This work supports the need to review the clinical and genetic spectra of DS in adults with epilepsy and unknown ID. The clinical consequences of this syndrome seem to have a functional rather than a structural basis, supported by the absence of specific neuropathological findings.

[Prognostic factors and profile in traumatic brain injury in the paediatric age]

INTRODUCTION

Traumatic brain injury (TBI) is a common cause of death and disability in the paediatric population, although the literature on the Spanish population is scarce. From the perspective of early vulnerability, recent research findings suggest that early brain injury has worse sequelae and a higher risk of impact.

AIMS

To analyse the intelligence profile, executive functions and behaviour, and examine the association between age at the time of the injury, severity of the TBI and environmental factors for cognitive and behavioural outcomes.

PATIENTS AND METHODS

Seventy-one participants with moderate to severe TBI, from 6 to 16 years of age, were assessed with measures of intelligence (intelligence quotient), executive functions and behaviour.

RESULTS

Children with TBI are at increased risk of disability in all aspects of intelligence, executive functions and behaviour. Children who suffered a traumatic brain injury in infancy and the preschool period had more overall effects on intelligence quotient and some aspects of the executive functions.

CONCLUSIONS

Socioeconomic and cultural factors are the best predictors for intelligence quotient and behaviour. These findings contribute to a better understanding of the sequelae of TBI in children, which will help in rehabilitation planning and re-adaptation to functional life.