Clinical phenotype of hereditary spastic paraplegia due to KIF1C gene mutations across life span

Hereditary spastic paraplegias (HSPs) are a group of genetic disorders resulting in pyramidal tract impairment, predominantly in lower limbs. KIF1C gene has recently been identified as one of the genetic causes of HSP and associated with pure or complicated HSP. We present three patients with complicated HSP from two unrelated families, who had early onset progressive cerebellar signs and developed pyramidal tract signs during follow-up. Whole exome sequencing in these patients followed by segregation analysis identified novel truncating KIF1C mutations (c.463C> T; p.R155^∗ and c.2478delA; p.Ala828Argfs^∗13). Neuroimaging findings showed cerebral and upper cervical spinal atrophy, bilateral symmetrical pyramidal tract involvement, and focal cerebral white matter lesions. Patients with KIF1C mutations may present with cerebellar signs and pyramidal findings may emerge later, therefore complicated HSP should be considered in the differential diagnosis of unidentified cases with cerebellar dysfunction.

A patient with mitochondrial disorder due to a novel mutation in MRPS22

MRPS22 gene defect is a very rare newly discovered mitochondrial disorder. We report a 4-month-old severely affected male infant with MRPS22 mutation. Whole exome sequencing revealed a novel homozygous splicing mutation c.339 + 5 G > A in MRPS22 gene. He has mild dysmorphism, hypotonia, developmental delay but not hypertrophic cardiomyopathy and tubulopathy which differ from other majority of reported patients. Therefore, hypertrophic cardiomyopathy and tubulopathy may not be considered as constant features of MRPS22. With this case report, we also present first symmetrical bilateral brainstem and medial thalamic lesions, and cerebellar and cerebral atrophy on a brain MR imaging follow-up of ten months.

Comparative transcriptome profiling approach to glean virulence and immunomodulation-related genes of Fasciola hepatica

BACKGROUND

Fasciola hepatica causes chronic liver disease, fasciolosis, leading to significant losses in the livestock economy and concerns for human health in many countries. The identification of F. hepatica genes involved in the parasite's virulence through modulation of host immune system is utmost important to comprehend evasion mechanisms of the parasite and develop more effective strategies against fasciolosis. In this study, to identify the parasite's putative virulence genes which are associated with host immunomodulation, we explored whole transcriptome of an adult F. hepatica using current transcriptome profiling approaches integrated with detailed in silico analyses. In brief, the comparison of the parasite transcripts with the specialised public databases containing sequence data of non-parasitic organisms (Dugesiidae species and Caenorhabditis elegans) or of numerous pathogens and investigation of the sequences in terms of nucleotide evolution (directional selection) and cytokine signaling relation were conducted.

RESULTS

NGS of the whole transcriptome resulted in 19,534,766 sequence reads, yielding a total of 40,260 transcripts (N₅₀ = 522 bp). A number of the parasite transcripts (n = 1,671) were predicted to be virulence-related on the basis of the exclusive homology with the pathogen-associated data, positive selection or relationship with cytokine signaling. Of these, a group of the virulence-related genes (n = 62), not previously described, were found likely to be associated with immunomodulation based on in silico functional categorisation, showing significant sequence similarities with various immune receptors (i.e. MHC I class, TGF-β receptor, toll/interleukin-1 receptor, T-cell receptor, TNF receptor, and IL-18 receptor accessory protein), cytokines (i.e. TGF-β, interleukin-4/interleukin-13 and TNF-α), cluster of differentiations (e.g. CD48 and CD147) or molecules associated with other immunomodulatory mechanisms (such as regulation of macrophage activation). Some of the genes (n = 5) appeared to be under positive selection (Ka/Ks > 1), imitating proteins associated with cytokine signaling (through sequence homologies with thrombospondin type 1, toll/interleukin-1 receptor, TGF-β receptor and CD147).

CONCLUSIONS

With a comparative transcriptome profiling approach, we have identified a number of potential immunomodulator genes of F. hepatica (n = 62), which are firstly described here, could be employed for the development of better strategies (including RNAi) in the battle against both zoonotically and economically important disease, fasciolosis.

Generating a detailed protein profile of Fasciola hepatica during the chronic stage of infection in cattle

Fasciola hepatica is a trematode helminth causing a damaging disease, fasciolosis, in ruminants and humans. Comprehensive proteomic studies broaden our knowledge of the parasite's protein profile, and provide new insights into the development of more effective strategies to deal with fasciolosis. The objective of this study was to generate a comprehensive profile of F. hepatica proteins expressed during the chronic stage of infection in cattle by building on previous efforts in this area. The approach included an improved sample preparation procedure for surface and internal layers of the parasite, the application of nano-UPLC-ESI-qTOF-MS (nano-ultra-performance LC and ESI quadrupole TOF MS) integrated with different acquisition methods and in silico database search against various protein databases and a transcript database including a new assembly of publically available EST. Of a total of 776 identified proteins, 206 and 332 were specific to the surface and internal layers of the parasite, respectively. Furthermore, 238 proteins were common to both layers, with comparative differences of 172 proteins detected. Specific proteins not previously identified in F. hepatica, but shown to be immunomodulatory or potential drug targets for other parasites, are discussed.