[Adult-onset sensory neuropathy and ataxia as a clinical manifestation of POLG gene mutations]

INTRODUCTION

Sensory ataxia is a frequent symptom in numerous neurological pathologies, being a frequent clinical manifestation in diseases related to genes influencing mitochondrial metabolism, such as POLG. The aim is to describe the differential characteristics of four patients with pathogenic variants in the POLG gene with clinical expression in the form of adult-onset ataxia and sensory neuropathy.

PATIENTS AND METHODS

We reviewed the clinical features of patients diagnosed with POLG pathogenic variants from a tertiary hospital.

RESULTS

Three men and one woman (mean age: 40 years; 27-46) with no family history were studied with symptoms for 10 years. All patients developed a gait disturbance related to sensory ataxia. All patients had oculomotor abnormalities. The neurophysiological study showed a sensory axonal neuropathy. Brain magnetic resonance imaging studies showed atrophy and cerebellar white matter lesion and muscle magnetic resonance imaging showed fatty substitution in thigh and calf muscles without a specific pattern. A molecular study revealed pathogenic variants in the POLG gene.

CONCLUSIONS

In cases of adult-onset sensory ataxia, the molecular analysis of the POLG gene should be considered, especially if associated with sensory neuropathy or ophthalmoparesis.

A variant in GRN of Spanish origin presenting with heterogeneous phenotypes

INTRODUCTION

The variant c.1414-1G>T in the GRN gene has previously been reported as probably pathogenic in subjects of Hispanic origin in the American continent.

METHODS

We report 5 families of Spanish origin carrying this variant, including the clinical, neuroimaging, and laboratory findings.

RESULTS

Phenotypes were strikingly different, including cases presenting with behavioral variant frontotemporal dementia, semantic variant primary progressive aphasia, rapidly progressive motor neuron disease (pathologically documented), and tremor-dominant parkinsonism. Retinal degeneration has been found in homozygous carriers only. Ex vivo splicing assays confirmed that the mutation c.1414-1G>T affects the splicing of the exon, causing a loss of 20 amino acids in exon 11.

CONCLUSIONS

We conclude that variant c.1414-1G>T of the GRN gene is pathogenic, can lead to a variety of clinical presentations and to gene dosage effect, and probably has a Spanish founder effect.

Lectin-like transcript 1 (LLT1) expression is associated with nodal metastasis in patients with head and neck cutaneous squamous cell carcinoma

The interaction of lectin-like transcript 1 (LLT1) with CD161 inhibits Natural Killer cell activation. Overexpression of LLT1 contributes to the immunosuppressive properties of tumor cells. However, there are little data about LLT1 expression in human solid tumors. The objective of this paper is to investigate the relationship between LLT1 expression with the clinicopathologic features and its impact on the prognosis of head and neck cutaneous squamous cell carcinoma (cSCC). LLT1 expression was analyzed on paraffin-embedded tissue samples obtained from 100 patients with cSCC by immunohistochemistry. The estimator of Fine and Gray was used to estimate the cumulative incidence curves for relapse. Proportional Hazard models and Hazard ratios (HRs) were used for studying the risk of tumor relapse and mortality. LLT1 strong expression was a significant risk factor for nodal metastasis with crude and adjusted ratios (HRs) of 3.40 (95% CI 1.39-9.28) and 3.25 (95% CI 1.15-9.16); and for cSCC specific death of 6.17 (95% CI 1.79-21.2) and 6.10 (95% CI 1.45-25.7). Strong LLT1 expression is an independent predictor of nodal metastasis and poor disease-specific survival and it might be helpful for risk stratification of patients with cSCC.

Sentinel lymph node biopsy plus wide local excision vs. wide location excision alone for primary cutaneous melanoma: a systematic review and meta-analysis

BACKGROUND

Sentinel lymph node biopsy and wide local excision of the primary melanoma (SLNB) is now a standard staging procedure for patients with melanomas 1 mm or more in thickness, but its therapeutic benefit is not clear.

OBJECTIVE

To determine whether there is an association between performance of SLNB and patient prognosis.

METHODS

Studies assessing the association between performance of SLNB and patient prognosis were pooled from MEDLINE, EMBASE, PubMed, Cochrane Database of Systematic Reviews and Google Scholar. From each study, first author's last name, publication year, origin country, type of study design, characteristics of participants and the Hazard risk (HR) for melanoma specific survival (MSS) with the corresponding 95% confidence interval (95% CI) were collected. Methodological assessment of the studies was evaluated using the Newcastle-Ottawa scale (NOS) and the 'Risk of bias' tool detailed in the Cochrane Handbook for Systematic Reviews of Interventions. Meta-analyses for the global HR were performed. In addition, in order to explore the sources of heterogeneity among the studies, sensitivity analyses are also provided.

RESULTS

A total of six studies with 8764 patients who had undergone SLNB and 11054 patients who had undergone wide location excision alone (WLEA) were identified for the analysis. The indicators suggest that the heterogeneity is low: τ²  = 0; H = 1 [1; 1.74]; I²  = 0% [0%; 66.5%]. Evidence for publication bias was not found (Egger's test P = 0.4654). The pooled MSS HR from fixed effects analysis was determined to be 0.88 (95% CI = 0.80-0.96).

CONCLUSIONS

Although no significant survival difference was observed in four of the six series, the pooling summary data from all the studies that deal with this issue suggested that SLNB is associated with a significantly better outcome compared with WLEA for localized melanoma.

Merkel cell carcinoma and Merkel cell polyomavirus: a systematic review and meta-analysis

Several observational studies have assessed the correlation between Merkel cell carcinoma and Merkel cell polyomavirus with variable results. The objective of this systematic review was to determine whether there is a correlation between Merkel cell carcinoma and Merkel cell polyomavirus. Studies assessing the relationship between Merkel cell carcinoma and Merkel cell polyomavirus from January 2008 to August 2014 were pooled from Medline, Embase, PubMed, Cochrane Database of Systemic Reviews and Google Scholar. From each study we collected the first author's last name, publication year, country of origin, type of study design, characteristics of participants, possible variables incorporated into the multivariable analyses and the risk ratio (RR) for Merkel cell carcinoma associated with Merkel cell polyomavirus combined with the corresponding 95% confidence interval (CI). Methodological assessment of the study was evaluated using the Newcastle-Ottawa scale. Crude RR was calculated from the data provided in each article. Meta-analyses for the global RR and for the proportion of positives in both case and control samples were performed. In addition, in order to explore the sources of heterogeneity among the studies, meta-regression and sensitivity analyses are also provided. A total of 22 studies were identified for the analysis. The pooled RR from random-effects analysis was determined to be 6.32 (95% CI, 4.02-9.93). Global proportions of positive samples were 0.79 (95% CI, 0.72-0.84) and 0.12 (95% CI, 0.08-0.19) in the case and control groups, respectively. The findings support the association between Merkel cell carcinoma and Merkel cell polyomavirus. However, a non-negligible percentage of positive results have been identified in controls. Some caution must be taken in the interpretation of these results because heterogeneity between studies was found.