Genetic Variation in the HN and SH Genes of Mumps Viruses: A Comparison of Strains from Mumps Cases with and without Neurological Symptoms

Abstract

BackgroundIt is known that mumps virus (MuV) strains may vary in their neurovirulent capacity, and certain MuV strains may be highly neurotropic. In animal models and epidemiological studies, mutations at specific amino acids (aa) have been proposed to be associated with neurovirulence. To assess whether these genetic variations can be observed in clinical samples from patients and if they correlate with neurovirulence as determined by clinical symptoms, 39 mumps patients with or without neurological symptoms were investigated.Principal FindingsRespiratory samples, oral fluids, throat swabs, and neurological and cerebrospinal fluid samples were tested by RT-PCR and products sequenced. Sequences of the entire small hydrophobic (SH) gene and the partial hemagglutinin-neuraminidase (HN) gene were compared.ConclusionsThe results showed there was no significant difference between the samples of the two groups of patients at the aa sites in either the HN protein or the SH protein, which have previously been hypothesized to be associated with neurovirulence or antigenicity. The occurrence of neurological symptoms of mumps does not appear to be due to a single point mutation in either the HN or SH gene.

Three cases of mumps virus and enterovirus coinfection in children with enteroviral meningitis

“…Accordingly, the Urabe AM9's use as a vaccine strain was discontinued in Japan, Canada, and the United Kingdom. [19] Based on these facts, it seems that the mumps vaccine strain may need an alteration in Iran to achieve better immunization after vaccination. Previous studies have indicated that amino acid substitutions at positions 335, 354, 356, 360, 464, and 466 in the HN region, and in positions 29 and 48 in the SH region, resulted in neuro-virulence of the virus.…”

“…Previous studies have indicated that amino acid substitutions at positions 335, 354, 356, 360, 464, and 466 in the HN region, and in positions 29 and 48 in the SH region, resulted in neuro-virulence of the virus. [19,42,43] The HN region is the main immunogenic part of the mumps genome and contains glycosylation sites in 3 epitope domains (aa265-288, aa329-340, aa352-360). [19] The SH region is the most variable part of the genome and is used for genotyping as well as for phylogenetic analysis of the virus.…”

“…[19,42,43] The HN region is the main immunogenic part of the mumps genome and contains glycosylation sites in 3 epitope domains (aa265-288, aa329-340, aa352-360). [19] The SH region is the most variable part of the genome and is used for genotyping as well as for phylogenetic analysis of the virus. [44,45] In this study, about 316 nucleotides of the SH and the first 162 nucleotides of the intravirion and transmembrane domains of the HN gene were sequenced.…”

“…[18] However, Urabe Am9 was later rejected because it was seen to cause postvaccination meningitis. [18,19] Several studies revealed that the occurrence of mutations, specifically in the HN and SH regions (including in antigenic and immunogenic epitopes), transformed the vaccine strain into its wild type, and may have led to the development of postvaccination meningitis. [20] The other large family of viruses that causes aseptic meningitis is the herpes virus.…”

Mumps in the Vaccination Age: Global Epidemiology and the Situation in Germany

“…However, there was no association of certain polymorphisms in the NH and the SH gene with the development of this side effect [20]. …”