Paternal age and specific neurological soft signs as reliable and valid neurobiological markers for the diagnosis of patients with schizophrenia

Advanced parental age at delivery and neurological soft signs (NSS) constitute risk factors for schizophrenia. The aim of the current study was to develop a neurobiological diagnostic index by combining them, and without the contribution of clinical symptomatology. The study sample included 133 patients suffering from schizophrenia according to DSM-IV-TR (77 males and 56 females; aged 33.55 ± 11.22 years old) and 122 normal controls (66 males and 56 females; aged 32.89 ± 9.91 years old). The assessment included the Neurological Evaluation Scale (NES), and a number of scales assessing the clinical symptoms and adverse effects. The statistical analysis included exploratory t-test, Pearson Correlation coefficient (R) and Discriminant Function Analysis (DFA). Exploratory t-tests and Pearson's R suggested that sex, parental age and NSS constitute independent components. On the basis of DFA results, the Psychotic Neurological Index was developed. At the cut-off PNI score of 8.5, sensitivity was equal to 94.74 and specificity to 93.44. The current is probably the first study to report on an easily obtainable diagnostic neurobiological marker with identifiable properties which is absolutely independent from the clinical manifestations and could serve in distinguishing between patients with schizophrenia and healthy controls with high efficacy.

β-Ureidopropionase deficiency due to novel and rare UPB1 mutations affecting pre-mRNA splicing and protein structural integrity and catalytic activity

β-Ureidopropionase is the third enzyme of the pyrimidine degradation pathway and catalyses the conversion of N-carbamyl-β-alanine and N-carbamyl-β-aminoisobutyric acid to β-alanine and β-aminoisobutyric acid, ammonia and CO₂. To date, only a limited number of genetically confirmed patients with a complete β-ureidopropionase deficiency have been reported. Here, we report on the clinical, biochemical and molecular findings of 10 newly identified β-ureidopropionase deficient individuals. Patients presented mainly with neurological abnormalities and markedly elevated levels of N-carbamyl-β-alanine and N-carbamyl-β-aminoisobutyric acid in urine. Analysis of UPB1, encoding β-ureidopropionase, showed 5 novel missense variants and two novel splice-site variants. Functional expression of the UPB1 variants in mammalian cells showed that recombinant ß-ureidopropionase carrying the p.Ala120Ser, p.Thr129Met, p.Ser300Leu and p.Asn345Ile variant yielded no or significantly decreased β-ureidopropionase activity. Analysis of the crystal structure of human ß-ureidopropionase indicated that the point mutations affect substrate binding or prevent the proper subunit association to larger oligomers and thus a fully functional β-ureidopropionase. A minigene approach showed that the intronic variants c.[364 + 6 T > G] and c.[916 + 1_916 + 2dup] led to skipping of exon 3 and 8, respectively, in the process of UPB1 pre-mRNA splicing. The c.[899C > T] (p.Ser300Leu) variant was identified in two unrelated Swedish β-ureidopropionase patients, indicating that β-ureidopropionase deficiency may be more common than anticipated.

Molecular analysis directs the prognosis, management and treatment of patients with xeroderma pigmentosum

Xeroderma pigmentosum (XP) is a well-studied disorder of (in most cases) nucleotide excision repair. The establishment in 2010 of a multidisciplinary XP clinic in the UK has enabled us to make a detailed analysis of genotype-phenotype relationships in XP patients and in several instances to make confident prognostic predictions. Splicing mutations in XPA and XPD and a specific amino acid change in XPD are associated with mild phenotypes, and individuals assigned to the XP-F group appear to have reduced pigmentation changes and a lower susceptibility to skin cancer than XPs in other groups. In an XP-C patient with advanced metastatic cancer arising from an angiosarcoma, molecular analysis of the tumour DNA suggested that immunotherapy, not normally recommended for angiosarcomas, might in this case be successful, and indeed the patient showed a dramatic recovery following immunotherapy treatment. These studies show that molecular analyses can improve the management, prognoses and therapy for individuals with XP.

A case with neurological abnormalities caused by Rickettsia raoultii in northwestern China

Background

The number of new rickettsial species are rapidly increasing, and increasing numbers of Rickettsia raoultii (R. raoultii) infection cases have been detected in humans. However, neurological abnormalities caused by R. raoultii are rarely reported, especially in northwestern China.

Case presentation

A 36-year-old Kazakh shepherd with an attached tick on part temporalis, presented with right eyelid droop, lethargy, fever, headache, fever (38.0–41.0 °C) and erythematous rash. The examination of cerebrospinal fluid (CSF) showed cerebrospinal pressure of 200 mm H₂O, leukocyte count of 300.0 × 10⁶/L, adenosine deaminase of 2.15 U/L, and total protein concentration of 0.93 g/L. The diagnosis of R. raoultii infection was confirmed by six genetic markers, and semi-quantified by enzyme-linked immunosorbent assay for rickettsial antigen. The patient gradually recovered after treatment with doxycycline and ceftriaxone. R. raoultii DNA was found both in a tick detached from this patient and in 0.18% (2/1107) of blood samples collected from local shepherds.

Conclusions

This is the first reported case with neurological abnormalities caused by R. raoultii in northwestern China. It is vital to detect rickettsial agents both in blood and CSF for tick bite patients with neurological abnormalities. Public health workers and physicians should pay attention to neurological abnormalities caused by Rickettsia.

Genetic Dissection and Clinical Features of MODY6 (NEUROD1-MODY)

PURPOSE OF REVIEW

MODY6 due to mutations in the gene NEUROD1 is very rare, and details on its clinical manifestation and pathogenesis are scarce. In this review, we have summarized all reported cases of MODY6 diagnosed by genetic testing, and examined their clinical features in detail.

RECENT FINDINGS

MODY6 is a low penetrant MODY, suggesting that development of the disease is affected by genetic modifying factors, environmental factors, and/or the effects of interactions of genetic and environmental factors, as is the case with MODY5. Furthermore, while patients with MODY6 can usually achieve good glycemic control without insulin, when undiagnosed they are prone to become ketotic with chronic hyperglycemia, and microangiopathy can progress. MODY6 may also cause neurological abnormalities such as intellectual disability. MODY6 should be diagnosed early and definitively by genetic testing, so that the correct treatment can be started as soon as possible to prevent chronic hyperglycemia.

Neurological soft signs in familial and sporadic schizophrenia

OBJECTIVE

Neurological soft signs (NSS) are a group of minor non-localizable neurological abnormalities found more often in patients with schizophrenia. The aim of the current study was investigate whether there is any difference in their manifestation in familial vs. sporadic schizophrenia.

MATERIAL AND METHODS

The study sample included 120 patients suffering from schizophrenia according to DSM-5 (71 males and 49 females; aged 32.79 ± 11.11 years old) and 110 normal controls (57 males and 53 females; aged 33.38 ± 10.14 years old). The assessment included the Neurological Evaluation Scale (NES) and the detailed investigation family history. The statistical analysis included exploratory Analysis of Covariance.

RESULTS

The results of the current study suggest that NSS are more frequent in familial cases of schizophrenia and are even more pronounced in cases with family history of psychosis in either first or second degree relatives.

DISCUSSION

Overall the results suggest the presence of a spectrum of increasing severity from healthy controls to sporadic cases, to cases with non-psychotic family history and eventually to cases with psychotic family history, rather than a categorical distribution.

Prevalence and correlates of neurological soft signs in healthy controls without family history of any mental disorder: A neurodevelopmental variation rather than a specific risk factor?

OBJECTIVE

Neurological soft signs (NSS) are a group of minor non-localizable neurological abnormalities found more often in patients with schizophrenia and other mental disorders. The aim of the current study was to investigate their prevalence and correlates in healthy controls without family history of any mental disorder.

MATERIAL AND METHODS

The study sample included 122 normal subjects (66 males and 56 females; aged 32.89 ± 9.91 years old). The assessment included the Neurological Evaluation Scale (NES), and a number of scales assessing the subthreshold symptoms (MADRS, STAI) and functioning (GAF). Data on a number of socio-demographic variables were also gathered. The statistical analysis included the development of basic statistics tables and the calculation of Pearson correlation coefficients.

RESULTS

The results of the current study suggest that more than half of the study sample manifested at least one NSS and approximately 5% more than four. Still, the reported prevalence and NES scores are lower form those reported in the literature probably because of the carefully selected study sample. There were no significant correlations between NSS and any socio-demographic or clinical variable.

DISCUSSION

The current study is the first to study NSS in subjects without family history of any mental disorder and reports the presence of frequent silent neurodevelopmental events in the general population, probably in the form of a neurodevelopmental variation and possibly a weak generic rather than specific risk factor.

Mild neurological impairment may indicate a psychomotor endophenotype in patients with borderline personality disorder

The aim of the present study was to determine whether patients with borderline personality disorder (BPD) show any neurological soft signs compared to healthy controls. Furthermore we sought to examine the role of common symptoms related to BPD, such as depression, anxiety or impulsivity, in association with neurological soft signs. Thirty patients with borderline personality disorder and thirty hospital-based controls were examined for neurological soft signs. The total score of neurological soft signs in BPD was significantly higher than controls. In terms of subscales, patients had higher scores in Sensory Integration and Motor Coordination and other neurological soft signs compared to control group. Multiple regression analysis showed that the impulsivity score was the best significant predictor of neurological soft signs in BPD. The increase of neurological soft signs in patients with BPD may address a non-focal neurological dysfunction in borderline personality disorder.

Differential gene expression during early development in brains of wildtype and biotinidase-deficient mice

Biotinidase deficiency is an autosomal recessively inherited disorder characterized by neurological and cutaneous abnormalities. Untreated individuals with biotinidase deficiency cannot recycle biotin from biocytin (N-biotinyl-ϵ-lysine), the proteolytic digestion product of protein-bound biotin. Biotin therapy can markedly resolve symptoms, or can prevent the development of symptoms if initiated early. To understand better the pathogenesis of the neurological problems in the disorder in humans, we have compared gene transcription changes during the first week post-birth in the brains of biotinidase-deficient, transgenic, knock-out mice at days 1 and 8 and compared to changes in wildtype mice at the same times. The knockout pups that were not supplemented with unconjugated biotin became symptomatic by day 8 and exhibiting failure to thrive. Wildtype pups remained asymptomatic under the same experimental conditions. We compared all four possible combinations and noted the most significant up- and down-regulated genes in the knockout animals at Day 8 compared to those at Day 1, reflecting the changes in gene expression over the first week of development. These alterations involved neurological development and immunological function pathways and provide some clues to avenues for further research. At this time, these preliminary analyses provide us with limited, but new information. However, with the development of new algorithms and programs examining various mechanisms and pathways in the central nervous system, these analyses may help us to understand better the role of biotinidase and the pathogenesis of biotinidase deficiency.

[Facial linear scleroderma associated with neurological abnormalities relating to microangiopathy]

BACKGROUND

Linear scleroderma is a fibrotic disease affecting the skin and sometimes the deeper tissues. We describe a case of scleroderma associated with neurological anomalies not previously reported in the literature.

PATIENTS AND METHODS

A 16-year-old male patient presented in 2009 for hemifacial linear scleroderma. Treatment with methotrexate for 14 months resulted in stabilization of the disease. In 2013, we noted worsening of the patient's skin lesions as well as homolateral ptosis. Head MRI revealed unilateral hemispherical signal abnormalities with T2 hypersignal in the basal gangliaand punctate foci of T2* hyposignal corresponding to microbleeds. In 2014 and 2015, the patient presented three brief episodes of right hemicorpus paresthesia (with temporary aphasia followed by headache during the first episode). The head MRI showed worsening of the anomalies, suggesting progressing cerebral microangiopathy.

DISCUSSION

Clinicians may not always be familiar with the neurological abnormalities associated with localized facial scleroderma even if such abnormalities are not uncommon (their exact prevalence is unknown). Clinical signs vary but, in most cases, the radiological features are calcifications and hyperintense foci of white matter lesions in T2. As far as we are aware, there have been no reports to date of microbleeding as observed in our patient. The worsening with time of these neurological anomalies of unknown origin does not appear to be correlated with the dermatological lesions. It is important for dermatologists be aware of these complications of facial linear scleroderma.