Heterozygous STUB1 mutation causes familial ataxia with cognitive affective syndrome (SCA48)

OBJECTIVE

To describe a new spinocerebellar ataxia (SCA48) characterized by early cerebellar cognitive-affective syndrome (CCAS) and late-onset SCA.

METHODS

This is a descriptive study of a family that has been followed for more than a decade with periodic neurologic and neuropsychological examinations, MRI, brain SPECT perfusion, and genetic analysis. Whole exome sequencing was performed in 3 affected and 1 unaffected family member and subsequently validated by linkage analysis of chromosome 16p13.3.

RESULTS

Six patients fully developed cognitive-affective and complete motor cerebellar syndrome associated with vermian and hemispheric cerebellar atrophy, suggesting a continuum from a dysexecutive syndrome slowly evolving to a complete and severe CCAS with late truncal ataxia. Three presymptomatic patients showed focal cerebellar atrophy in the vermian, paravermian, and the medial part of cerebellar lobes VI and VII, suggesting that cerebellar atrophy preceded the ataxia, and that the neurodegeneration begins in cerebellar areas related to cognition and emotion, spreading later to the whole cerebellum. Among the candidate variants, only the frameshift heterozygous c.823_824delCT STUB1 (p.L275Dfs*16) pathogenic variant cosegregated with the disease. The p.L275Dfs*16 heterozygous STUB1 pathogenic variant leads to neurodegeneration and atrophy in cognition- and emotion-related cerebellar areas and reinforces the importance of STUB1 in maintaining cognitive cerebellar function.

CONCLUSIONS

We report a heterozygous STUB1 pathogenic genetic variant causing dominant cerebellar ataxia. Since recessive mutations in STUB1 gene have been previously associated with SCAR16, these findings suggest a previously undescribed SCA locus (SCA48; MIM# 618093).

Preliminary observations on the spawning conditions of the European amphioxus (Branchiostoma lanceolatum) in captivity

Members of the subphylum Cephalochordata, which include the genus Branchiostoma (i.e. amphioxus), represent the closest living invertebrate relatives of the vertebrates. To date, developmental studies have been carried out on three amphioxus species (the European Branchiostoma lanceolatum, the East Asian B. belcheri, and Floridian-Caribbean B. floridae). In most instances, adult animals have been collected from the field during their ripe season and allowed (or stimulated) to spawn in the laboratory. In any given year, dates of laboratory pawning have been limited by two factors. First, natural populations of these three most studied species of amphioxus are ripe, at most, for only a couple of months each year and, second, even when apparently ripe, animals spawn only at unpredictable intervals of every several days. This limited supply of living material hinders the development of amphioxus as a model system because this limitation makes it more difficult to work out protocols for new laboratory techniques. Therefore we are developing laboratory methods for increasing the number of amphioxus spawning dates per year. The present study found that a Mediterranean population of B. lanceolatum living near the Franco-Spanish border spawned naturally at the end of May and again at the end of June in 2003. Re-feeding experiments in the laboratory demonstrated that the gonads emptied at the end of May refilled with gametes by the end of June. We also found that animals with large gonads (both, obtained from the field and kept and fed at the laboratory during several weeks) could be induced to spawn in the laboratory out of phase with the field population if they were temperature shocked (spawning occurred 36 hours after a sustained increase in water temperature from 19 degrees C to 25 degrees C).

No more than 14: the end of the amphioxus Hox cluster

The Hox gene cluster has been a key paradigm for a generation of developmental and evolutionary biologists. Since its discovery in the mid-1980's, the identification, genomic organization, expression, colinearity, and regulation of Hox genes have been immediate targets for study in any new model organism, and metazoan genome projects always refer to the structure of the particular Hox cluster(s). Since the early 1990's, it has been dogma that vertebrate Hox clusters are composed of thirteen paralogous groups. Nonetheless, we showed that in the otherwise prototypical cephalochordate amphioxus (Branchiostoma floridae), the Hox cluster contains a fourteenth Hox gene, and very recently, a 14^th Hox paralogous group has been found in the coelacanth and the horn shark, suggesting that the amphioxus cluster was anticipating the finding of Hox 14 in some vertebrate lineages. In view of the pivotal place that amphioxus occupies in vertebrate evolution, we thought it of considerable interest to establish the limits of its Hox gene cluster, namely resolution of whether more Hox genes are present in the amphioxus cluster (e.g., Hox 15). Using two strategies, here we report the completion and characterization of the Hox gene content of the single amphioxus Hox cluster, which encompasses 650 kb from Hox1 to Evx. Our data have important implications for the primordial Hox gene cluster of chordates: the prototypical nature of the single amphioxus Hox cluster makes it unlikely that additional paralogous groups will be found in any chordate lineage. We suggest that 14 is the end.

OMENTAL INFARCTION: SURGICAL or CONSERVATIVE TREATMENT? A CASE REPORTS and CASE SERIES SYSTEMATIC REVIEW

BACKGROUND

Omental infarction (OI) is an infrequent cause of acute abdominal pain and there is no consensus on whether conservative or surgical treatment is the best strategy when performing positive CT diagnosis.

OBJECTIVES

To assess which of the two treatments is the most commonly adopted and compare outcomes in terms of success rate in resolution of symptoms and hospital length of stay.

ELIGIBILITY CRITERIA

Case report and case series of patients with abdominal pain and positive diagnosis by CT of omental infarction.

DATA SOURCES

PubMed, Science Direct and Google Scholar in combination with cross-referencing searches and manual searches of eligible articles from January 2000 to June 2018.

PARTICIPANTS

Patients older than 18 years of age.

METHODS

Patient characteristics and results were summarized descriptively. Categorical variables were assessed by chisquare test or Fischer's exact test, and continuous variables by the Wilcoxon-Mann-Whitney or Kruskal-Wallis test. Risk factors for failure of the conservative management were identified using multivariate logistic regression.

RESULTS

90 articles were included in the final analysis (146 patients). 107 patients (73.3%) received conservative treatment with a failure rate of 15.9% (patients needing surgery) and 39 patients (26.7%) received surgery as first treatment. The mean hospital length of stay was 5.1 days for the conservative treatment group and 2.5 days for the surgery group with statistically significant differences (p = 0.00). Younger age and white blood cells count ≥12000/μl were predictive factors of conservative treatment failure.

CONCLUSIONS

Although conservative treatment is effective in most patients, surgery has advantages in terms of hospital length of stay.

Late-onset vestibulocerebellar ataxia: clinical and genetic studies in a long follow-up series of 50 patients

BACKGROUND

To describe the epidemiology, clinical features, degree of disability and genetic characteristics of a cohort of patients with a vestibulo-cerebellar ataxia of very late onset (LOVCA).

METHODS

We analysed the clinical, radiological, and genetic characteristics of a cohort of 50 patients with LOVCA. Where possible, patients were followed over the full course of the disease, including clinical, and molecular genetic analysis of genes known to cause episodic ataxia.

RESULTS

Ten patients are familial and 40 sporadic. Forty-three patients had an episodic onset, with episodes of gait ataxia characterized especially by sudden instability with downbeat nystagmus, visual symptoms, dizziness, and falls. Progression began on average 1.5 years after the onset of episodes. Of the patients followed over the full course of the disease, 87% became disabled. Women seem more prone to disability than men. An FGF14 intronic GAA repeat expansion was found in 61% of patients with available DNA. The prevalence of LOVCA is 5.03/105 inhabitants. Treatment with 4-aminopyridine reduced the number and severity of episodes.

CONCLUSION

LOVCA appears after the age of 50 and commonly leads to an inability to stand up and walk. The disease caused mild atrophy only in half of the patients and few changes were observed by MRI. The most common genetic cause was a heterozygous GAA expansion in FGF14 (SCA27B). One third of our patients have no aetiological diagnosis. Disability seems to be a result of the complete loss of the vestibulocerebellar function, which is presumably a result of degeneration of this system.