Virological testing of cerebrospinal fluid in children aged less than 14 years with a suspected central nervous system infection: A retrospective study on 304 consecutive children from January 2012 to May 2015.

OBJECTIVE: The study aimed to describe the prevalence of HSV DNA, VZV DNA, Enterovirus RNA, Parechovirus RNA, CMV DNA, EBV DNA, adenovirus DNA, HHV-6 DNA, HHV-7 DNA, HHV-8 DNA and Parvovirus B19DNA in children aged less 14 years with a suspected viral infection of the central nervous system in a clinical practice setting. METHODS: Between January 2012 and May 2015, cerebrospinal fluids from 304 children were tested with an in-house real-time PCR method. RESULTS: A positive PCR was detected in 64 subjects (21%): the mean number of tests performed in patients who showed a viral infection was 7.5, significantly higher (p = 0.001) with respect to that reported in negative samples (6.4). Enterovirus is the leading virus detected: 12 out of the 37 positive children reported were newborns (85.7% of all the newborns with a positive result). The second most frequently identified virus was HHV-7 (5 positive PCR out of 105 samples tested, 4.8%, if we excluded a child with a concomitant S. pneumoniae isolated), a prevalence significantly higher with respect to VZV (p = 0.02) and to CMV (p = 0.04). HHV-6 was the third most commonly identified aetiology (4.2%). All children were immunocompetent. SIGNIFICANCE: Only a minority of children had a specific viral aetiology identified: the rate of HHV-7 positivity suggests a routine testing of these viruses within the diagnostic algorithm in immunocompetent paediatric patients. This approach could help to define the clinical role of this herpesvirus.

A novel type I factor X variant (factor X Cys350Phe) due to loss of a disulfide bond in the catalytic domain.

We report a novel mutation within the coagulation factor X (FX) that we have designated FX Padua 4. The phenotype and genotype of the proband and family members were studied. The proband was a child affected by a complex neurological syndrome who, after birth, experienced severe bleeding. The proband showed a laboratory pattern characterized by a severe reduction of FX activity and FX antigen, suggesting a true deficiency. Molecular analysis disclosed a new FX mutation localized in the catalytic domain responsible for a Cys350Phe substitution. The proband was homozygous for this mutation. The proband's mother and father showed a heterozygous pattern and had approximately one-half the normal FX activity and FX antigen. Residual purified FX Cys350Phe had an identical behavior to normal FX as showed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Molecular modeling confirms that the mutation leads to the disruption of a disulfide bridge in the catalytic region of FX. Comparison with other topologically equivalent mutations in other vitamin K-dependent proteins suggests that this disruption could adversely affect protein folding/stability, accounting for the cross-reactive material negative phenotype.