Epilepsy and EEG Abnormalities in Congenital Zika Syndrome.

SUMMARY: The congenital Zika syndrome is a new entity of a group of etiologies that can lead to microcephaly and other brain damages during pregnancy, such as toxoplasmosis, rubeola, cytomegalovirus, and herpes simplex. The Zika virus crosses the placental barrier and, predominantly, affects neuronal progenitor cells. This disruptive process results in severe cortical developmental disorder, calcifications, cortical and subcortical atrophies, and malformations of the cerebellum, brain stem, and spinal cord. Children with congenital Zika syndrome have a set of clinical findings, such as cerebral palsy, dysphagia, orthopedic deformities, visual and auditory impairment, and, rarely, hydrocephalus. Because of the severity of brain lesions, epilepsy is a common finding and a frequent cause of increased morbidity. The prevalence of epilepsy in different series of patients ranges from 37.7% to 71.4%. The aim of this study is to review the studies published so far regarding epilepsy and the EEG pattern in series of patients with congenital Zika syndrome.

Intragenic variants in the SMN1 gene determine the clinical phenotype in 5q spinal muscular atrophy.

OBJECTIVE: The aim of the study was to report the proportion of homozygous and compound heterozygous variants in the survival motor neuron 1 (SMN1) gene in a large population of patients with spinal muscular atrophy (SMA) and to correlate the severity of the disease with the presence of specific intragenic variants in SMN1 and with the SMN2 copy number. METHODS: Four hundred fifty Brazilian patients with SMA were included in a retrospective study, and clinical data were analyzed compared with genetic data; the SMN2 copy number was obtained by multiplex ligation-dependent probe amplification and pathogenic variants in SMN1 by next-generation sequencing. RESULTS: Four hundred two patients (89.3%) presented homozygous exon 7-SMN1 deletion, and 48 (10.7%) were compound heterozygous for the common deletion in one allele and a point mutation in the other allele. Recurrent variants in exons 3 and 6 (c.460C>T, c.770_780dup and c.734_735insC) accounted for almost 80% of compound heterozygous patients. Another recurrent pathogenic variant was c.5C>G at exon 1. Patients with c.770_780dup and c.734_735insC had a clinical phenotype correlated with SMN2 copy number, whereas the variants c.460C>T and c.5C>G determined a milder phenotype independently of the SMN2 copies. CONCLUSIONS: Patients with specific pathogenic variants (c.460C>T and c.5C>G) presented a milder phenotype, and the SMN2 copy number did not correlate with disease severity in this group.