Analysis of genetic diversity of Leuciscus leuciscus baicalensis using novel microsatellite markers with cross-species transferability

We used next-generation sequencing technology to characterize 19 genomic simple sequence repeat (SSR) markers and 11 expressed sequence tag (EST) SSR markers from Leuciscus leuciscus baicalensis, a small freshwater fish that is widely distributed in Xinjiang, China. Primers were used to test for polymorphisms in three L. leuciscus baicalensis populations in Xinjiang. There were 4-27 (average 11.3) alleles (N_A), the expected heterozygosity (H_E) was 0.36-0.94 (average 0.75 ± 0.14), the observed heterozygosity (H_O) was 0.37-1.00 (average 0.68 ± 0.18), and the polymorphism information content (PIC) was 0.31-0.93 (average 0.71). The averages of H_E and PIC for the EST-SSR markers were slightly lower than for the genomic SSR markers. Genetic analysis of the three populations showed similar results for PIC, H_E, and N_A. Amplifications were performed in nine other species; the top three transferability values were for Rutilus lacustris (80%), Leuciscus idus (76.7%), and Phoxinus ujmonensis (63.3%), with the following average values: PIC (0.56, 4.46, and 0.52); N_A (0.40, 3.00, and 0.32); and H_O (0.44, 2.74, and 0.22), respectively. L. leuciscus baicalensis is one of the most important commercial fish in Xinjiang, but in recent years, fishery resources have decreased sharply owing to water conservation projects, unreasonable utilization, and invasion by alien species. These novel SSR markers are appropriate for studies involving fingerprinting, gene flow, genetic diversity, population structure, and molecular-assisted breeding, and could contribute to the conservation of L. leuciscus baicalensis.

High glucose concentration abrogates sevoflurane post-conditioning cardioprotection by advancing mitochondrial fission but dynamin-related protein 1 inhibitor restores these effects

AIM

Hyperglycaemia-induced cell injury is a primary cause of cardiovascular complications in patients with diabetes. In vivo studies demonstrated that sevoflurane post-conditioning (SpostC) was cardioprotective against ischaemia/reperfusion injury, which was blocked by hyperglycaemia. This study investigated whether high glucose concentration abrogated SpostC cardioprotection in vitro by advancing mitochondrial fission and whether mitochondrial division inhibitor-1 (Mdivi-1) restored SpostC cardioprotection in cultured primary neonatal rat cardiomyocytes (NCMs).

METHODS

Primary cultured NCMs in low and high glucose concentrations were subjected to hypoxia/reoxygenation (H/R) injury. SpostC was carried out by adding 2.4% sevoflurane to the cells at the beginning of reoxygenation for 15 min. Cell viability, lactate dehydrogenase (LDH) level, cell death, mitochondrial morphology, mitochondrial membrane potential and mitochondrial permeability transition pore (mPTP) opening level, as well as fission- and fusion-related proteins, were measured after H/R injury. Mdivi-1 treatment was performed 40 min before hypoxia to inhibit DRP1.

RESULTS

SpostC protected cultured cardiomyocytes by increasing cell viability and reducing the LDH level and cell death following H/R, but high glucose concentration eliminated the cardioprotective effect. High glucose concentration abrogated SpostC cardioprotection via mitochondrial fragmentation (evidenced by decreased mitochondrial interconnectivity and elongation) and facilitation of mPTP opening. Decreased mitochondrial membrane potential was investigated with increased DRP1, FIS1 and MFN2 and decreased MFN1 and OPA1 expressions. Mdivi-1 (100 μmol L^-1 ) inhibited excessive mitochondrial fission and restored the cardioprotective effect of SpostC in high glucose conditions.

CONCLUSION

SpostC-induced cardioprotection against H/R injury was impaired under high glucose concentrations, but the inhibition of excess mitochondrial fission restored these effects.

Kaempferol inhibited VEGF and PGF expression and in vitro angiogenesis of HRECs under diabetic-like environment

Diabetic retinopathy (DR) is one of the common and specific microvascular complications of diabetes. This study aimed to investigate the anti-angiogenic effect of kaempferol and explore its underlying molecular mechanisms. The mRNA expression level of vascular endothelial growth factor (VEGF) and placenta growth factor (PGF) and the concentrations of secreted VEGF and PGF were measured by qTR-PCR and ELISA assay, respectively. Human retinal endothelial cells (HRECs) proliferation, migration, and sprouting were measured by CCK-8 and transwell, scratching wound, and tube formation assays, respectively. Protein levels were determined by western blot. High glucose (25 mM) increased the mRNA expression levels of VEGF and PGF as well as the concentrations of secreted VEGF and PGF in HRECs, which can be antagonized by kaempferol (25 µM). Kaempferol (5-25 µM) significantly suppressed cell proliferation, migration, migration distance and sprouting of HRECs under high glucose condition. The anti-angiogenic effect of kaempferol was mediated via downregulating the expression of PI3K and inhibiting the activation of Erk1/2, Src, and Akt1. This study indicates that kaempferol suppressed angiogenesis of HRECs via targeting VEGF and PGF to inhibit the activation of Src-Akt1-Erk1/2 signaling pathway. The results suggest that kaempferol may be a potential drug for better management of DR.

Randomized controlled trials of serotonin-norepinephrine reuptake inhibitor in treating major depressive disorder in children and adolescents: a meta-analysis of efficacy and acceptability

New generation antidepressant therapies, including serotonin-norepinephrine reuptake inhibitor (SNRIs), were introduced in the late 1980s; however, few comprehensive studies have compared the benefits and risks of various contemporary treatments for major depressive disorder (MDD) in young patients. A comprehensive literature search of PubMed, Cochrane, Embase, Web of Science, and PsycINFO databases was conducted from 1970 to January 2015. Only clinical trials that randomly assigned one SNRI or placebo to patients aged 7 to 18 years who met the diagnostic criteria for major depressive disorder were included. Treatment success, dropout rate, and suicidal ideation/attempt outcomes were measured. Primary efficacy was determined by pooling the risk ratios (RRs) of treatment response and remission. Acceptability was determined by pooling the RRs of dropouts for all reasons and for adverse effects as well as suicide-risk outcomes. Five trials with a total of 973 patients were included. SNRIs were not significantly more effective than placebo for treatment response but were for remission. The comparison of patients taking SNRIs that dropped out for all reasons and those taking placebo did not reach statistical significance. Significantly more patients taking SNRIs dropped out for adverse effects than those taking placebo. No significant difference was found in suicide-related risk outcomes. SNRI therapy does not display a superior efficacy and is not better tolerated compared to placebo in these young patients. However, duloxetine has a potential beneficial effect for depression in young populations, showing a need for further research.

Molecular cloning, characterization, and expression analysis of ghrelin and cholecystokinin in the pigeon (Columba livia)

Ghrelin and cholecystokinin (CCK) are multifunctional peptides. In the current study, complete sequences of ghrelin (800 bp) and CCK (739 bp) were firstly cloned in Columba livia by using rapid amplification of cDNA ends (RACE) method. The open reading frames of ghrelin (351bp) and CCK (393bp) encoded 116 amino acids and 130 amino acids, respectively. Sequence comparison indicated that pigeon ghrelin and CCK shared high identity with those reported in other avian species. Quantitative real-time PCR analysis found that ghrelin and CCK mRNAs expressed in three intestinal segments of pigeon during development. Both ghrelin and CCK showed generally higher expressions at days posthatch than embryonic periods regardless of intestinal segments. In duodenum and ileum, the expressions of ghrelin and CCK mRNA reached the peak values at 8 d posthatch. Jejunum CCK mRNA level increased linearly after hatching, and reached the highest point at posthatch 28 d. Based on documented effects of long chain fatty acids (LCFAs) on pigeon ghrelin and CCK expression were also investigated in vitro. Higher concentrations (50 μM or 250 μM) of linoleic acid, α-linolenic acid or arachidonic acid can significantly increase ghrelin mRNA level in pigeon jejunum. However, for oleic acid, the induction of ghrelin gene expressions needed a lower concentration (5 μM). 5 μM of linoleic acid, α-linolenic acid or arachidonic acid and 250 μM palmitic acid repressed CCK expression significantly. A higher concentration (250 μM) of oleic acid or α-linolenic acid can up-regulate CCK mRNA level significantly. Our results indicated that ghrelin and CCK may act key functions in pigeon intestine development and their expressions could be regulated by LCFAs.

Identification of sex-specific urinary biomarkers for major depressive disorder by combined application of NMR- and GC-MS-based metabonomics

Women are more vulnerable to major depressive disorder (MDD) than men. However, molecular biomarkers of sex differences are limited. Here we combined gas chromatography-mass spectrometry (GC-MS)- and nuclear magnetic resonance (NMR)-based metabonomics to investigate sex differences of urinary metabolite markers in MDD, and further explore their potential of diagnosing MDD. Consequently, the metabolite signatures of women and men MDD subjects were significantly different from of that in their respective healthy controls (HCs). Twenty seven women and 36 men related differentially expressed metabolites were identified in MDD. Fourteen metabolites were changed in both women and men MDD subjects. Significantly, the women-specific (m-Hydroxyphenylacetate, malonate, glycolate, hypoxanthine, isobutyrate and azelaic acid) and men-specific (tyrosine, N-acetyl-d-glucosamine, N-methylnicotinamide, indoxyl sulfate, citrate and succinate) marker panels were further identified, which could differentiate men and women MDD patients from their respective HCs with higher accuracy than previously reported sex-nonspecific marker panels. Our findings demonstrate that men and women MDD patients have distinct metabonomic signatures and sex-specific biomarkers have promising values in diagnosing MDD.

Free choice feeding of whole grains in meat-type pigeons: 1. effect on performance, carcass traits and organ development

The effects of 5 different feeding systems on the performance, carcass traits and organ development were studied in pigeon squabs. The 5 treatments were (1) whole grains of maize, pea and wheat plus concentrate feed; (2)whole grains of maize and wheat plus concentrate feed (CWC); (3) whole grains of maize and pea plus concentrate feed; (4)whole grain of maize plus concentrate feed (CC); and (5) compound feed (CF). Feed intake of parent pigeons increased significantly from 0 to 21 d and it was higher in the CF treatment. Body weight of squabs in the CWC treatment was the highest among the 5 treatments in 4 weeks. Body weight losses of parental pigeons during the rearing period were not significantly different among the 5 treatments. Protein intake in CC and CWC treatments was lower than that of the other three treatments. The CWC treatment had the highest daily weight gain and the lowest feed conversion ratio. Treatments were statistically similar in the relative weight of carcass, breast and thigh. CF had the lower relative weight of abdominal fat. Relative weight of gizzard in the CF treatment was significantly lower than that of CWC. It was concluded that the application of free choice feeding of whole grains of maize and wheat plus concentrate feed increased the body weight of 28-d-old pigeon squabs and decreased the feed conversion rate of parent pigeons. This feeding strategy could be commercially interesting in meat-type pigeon production.

[Epidemiological study of hypertension in Dongxiang population of Dongxiang county in Gansu province]

Objective: To investigate the prevalence, awareness, treatment and control rate of hypertension among Dongxiang population of Dongxiang county in Gansu province, and analyze risk factors of hypertension in this population. Methods: A total of 1 879 Dongxiang residents of Dongxiang county in Gansu province aged 18 years and over were selected in one town and eight villages by random cluster method from April to June in 2014. All subjects were interviewed and physical examination including blood pressure measurement was performed. Multivariate logistic regression analysis was used to analyze the risk factors of hypertension. Results: Prevalence of hypertension in this population was 21.4%(402/1 879). Prevalence of hypertension increased with aging and was 7.9%(35/441) in 18-39 years old people, and 20.2%(151/749)in 40-59 years old people, and 31.3%(216/689)in ≥60 years old people (P<0.01). There were no gender (male vs. female) difference in prevalence of hypertension in 18-39 years old group (8.0%(20/249)vs. 7.8%(15/192), P>0.05) and 40-59 years old group (19.8%(78/393) vs. 20.5%(73/356), P>0.05), while the prevalence of hypertension was significantly higher in male than in female(34.2%(123/360) vs. 28.3%(93/329), P<0.01)in ≥60 years old group. Prevalence of hypertension was also significantly higher in rural area residents than in county town residents (23.4%(255/1 090) vs.18.6%(147/789), P<0.01). The rates of awareness, treatment and control of hypertension in this population were 24.4%(98/402), 14.7%(59/402) and 5.0%(20/402), respectively. Rates of awareness (22.7%(58/255)vs. 27.2%(40/147), P<0.01), treatment(13.3%(34/255)vs. 17.0%(25/147), P<0.05) and control(3.9%(10/255)vs. 6.8%(10/147), P<0.05) were significantly lower in rural area residents than in county residents. Multivariate logistic regression analysis showed that age, family history of hypertension, high body mass index, less physical activity and more static state were risk factors of hypertension in this population(P<0.05 or 0.01). Conclusions: Prevalence of hypertension is high and awareness, treatment and control rates of hypertension are low in adult residents of Dongxiang county in Gansu province. Hypertension prevention focusing on risk factors control and treatment strategies should be enhanced in this population.

Autologous hematopoietic stem cell transplantation in patients with end-stage liver disease: a 5-year follow-up study of 48 patients

OBJECTIVE

To investigate the long-term therapeutic effect of autologous hematopoietic stem cell transplantation in patients with End-stage Liver Disease (ESLD).

PATIENTS AND METHODS

Forty-eight ESLD patients underwent autologous CD34+ stem cell transplantation were retrospectively reviewed. Changes in clinical and biochemical data, complications, and quality of life were monitored at 3, 6, 12, 36, and 60 months following the stem cell transplantation. Liver biopsies were obtained for histopathological analysis using Ishak system.

RESULTS

Marked improvement in clinical and biochemical data was observed during the long-term follow-up. Serum albumin was significantly increased (p<0.001), while total serum bilirubin, prothrombin time (PT), and international normalized ratio (INR) were all significantly decreased (p<0.001). Ishak inflammation and fibrosis scores were significantly decreased with the increased time (p<0.001). The number of patients with ascites, model of end-stage liver disease (MELD) score, Child-Pugh class, and indocyanine green (ICG) score were all markedly reduced with increased time. Meanwhile, the quality of life score of the patients was significantly increased (p<0.001). Six patients died during the 5-years follow-up, and complications occurred in 17 patients. The incidence of complications was significantly associated with mortality of the patients (p<0.05).

CONCLUSIONS

The study provided the evidence that autologous CD34+ stem cell transplantation could offer a long-term therapeutic benefit to patients with ESLD. The complications occurred during the process was significantly associated with survival of the patients. Future studies on a large cohort of patients are needed to confirm the long-term effect of stem cell therapy on ESLD.

Gut microbiome remodeling induces depressive-like behaviors through a pathway mediated by the host's metabolism

Major depressive disorder (MDD) is the result of complex gene-environment interactions. According to the World Health Organization, MDD is the leading cause of disability worldwide, and it is a major contributor to the overall global burden of disease. However, the definitive environmental mechanisms underlying the pathophysiology of MDD remain elusive. The gut microbiome is an increasingly recognized environmental factor that can shape the brain through the microbiota-gut-brain axis. We show here that the absence of gut microbiota in germ-free (GF) mice resulted in decreased immobility time in the forced swimming test relative to conventionally raised healthy control mice. Moreover, from clinical sampling, the gut microbiotic compositions of MDD patients and healthy controls were significantly different with MDD patients characterized by significant changes in the relative abundance of Firmicutes, Actinobacteria and Bacteroidetes. Fecal microbiota transplantation of GF mice with 'depression microbiota' derived from MDD patients resulted in depression-like behaviors compared with colonization with 'healthy microbiota' derived from healthy control individuals. Mice harboring 'depression microbiota' primarily exhibited disturbances of microbial genes and host metabolites involved in carbohydrate and amino acid metabolism. This study demonstrates that dysbiosis of the gut microbiome may have a causal role in the development of depressive-like behaviors, in a pathway that is mediated through the host's metabolism.

Inflammasome signaling affects anxiety- and depressive-like behavior and gut microbiome composition

The inflammasome is hypothesized to be a key mediator of the response to physiological and psychological stressors, and its dysregulation may be implicated in major depressive disorder. Inflammasome activation causes the maturation of caspase-1 and activation of interleukin (IL)-1β and IL-18, two proinflammatory cytokines involved in neuroimmunomodulation, neuroinflammation and neurodegeneration. In this study, C57BL/6 mice with genetic deficiency or pharmacological inhibition of caspase-1 were screened for anxiety- and depressive-like behaviors, and locomotion at baseline and after chronic stress. We found that genetic deficiency of caspase-1 decreased depressive- and anxiety-like behaviors, and conversely increased locomotor activity and skills. Caspase-1 deficiency also prevented the exacerbation of depressive-like behaviors following chronic stress. Furthermore, pharmacological caspase-1 antagonism with minocycline ameliorated stress-induced depressive-like behavior in wild-type mice. Interestingly, chronic stress or pharmacological inhibition of caspase-1 per se altered the fecal microbiome in a very similar manner. When stressed mice were treated with minocycline, the observed gut microbiota changes included increase in relative abundance of Akkermansia spp. and Blautia spp., which are compatible with beneficial effects of attenuated inflammation and rebalance of gut microbiota, respectively, and the increment in Lachnospiracea abundance was consistent with microbiota changes of caspase-1 deficiency. Our results suggest that the protective effect of caspase-1 inhibition involves the modulation of the relationship between stress and gut microbiota composition, and establishes the basis for a gut microbiota-inflammasome-brain axis, whereby the gut microbiota via inflammasome signaling modulate pathways that will alter brain function, and affect depressive- and anxiety-like behaviors. Our data also suggest that further elucidation of the gut microbiota-inflammasome-brain axis may offer novel therapeutic targets for psychiatric disorders.

Focused screening of mitochondrial metabolism reveals a crucial role for a tumor suppressor Hbp1 in ovarian reserve

Granulosa cells (GCs) are tightly associated with fertility and the fate of ovarian follicles. Mitochondria are the central executers of apoptosis. However, the genetic basis underlying mitochondrial modulation in GCs during the ovarian development is poorly understood. Here, CRISPR/Cas9-mediated genetic screening was used to identify genes conferring mitochondrial metabolism in human GCs. The results uncovered roles for several tumor suppressors, including HBP1, in the augmentation of mitochondrial function. Focused analysis revealed that high-mobility group (HMG)-box transcription factor 1 (Hbp1) levels regulate mitochondrial biogenesis, which is associated with global changes in transcription including Tfam. The systemic or granulosa-specific but not oocyte-specific ablation of Hbp1 promoted follicle growth and oocyte production, and is associated with the reduced apoptotic signals in mouse GCs. Consistent with increased mitochondrial function and attenuated GC apoptosis, the regulation of Hbp1 conferred substantial protection of ovarian reserve. Thus, the results of the present study provide a critical target to understand the control of the reproductive lifespan.

Individual differences in rumination in healthy and depressive samples: association with brain structure, functional connectivity and depression

BACKGROUND

Rumination is an important cognitive risk factor for onset and relapse of depression. However, no studies have employed a dimensional approach in investigating the neural correlates of rumination and the relationship with depression.

METHOD

Non-clinical healthy subjects (n = 306), who completed the classical rumination and depression scales, were studied using voxel-based morphometry and regional homogeneity (ReHo). Subsequently, mediation analysis was conducted to examine the influence of rumination on the relationship between brain structure and depression. Moreover, depressive patients (n = 60) and a control group (n = 63) of comparable age and education were studied with regions of interest that were identified in the healthy individuals.

RESULTS

For healthy individuals, regional grey-matter volume (rGMV) of dorsolateral prefrontal cortex (DLPFC) and parahippocampal gyrus (PHG) were positively correlated with rumination. In addition, rumination had a mediating effect on the relationship between the DLPFC and PHG and depression. Moreover, ReHo analysis showed that rumination had a significantly negative correlation with functional homogeneity of DLPFC. However, compared to the control group, depressed patients showed significant decrease of rGMV in the DLPFC and PHG and there was a significant negative correlation between DLPFC volume and depressive rumination.

CONCLUSIONS

Increased DLPFC volume (decreased ReHo) in healthy individuals while decreased in depression indicated the trend of DLPFC from inefficient inhibition ('overload state') to impaired regulatory mechanism ('paralysis state'). This finding might elucidate when and why healthy individuals would develop sustained negative mood and depression eventually.

Specific alterations in plasma proteins during depressed, manic, and euthymic states of bipolar disorder

Bipolar disorder (BD) is a common psychiatric mood disorder affecting more than 1-2% of the general population of different European countries. Unfortunately, there is no objective laboratory-based test to aid BD diagnosis or monitor its progression, and little is known about the molecular basis of BD. Here, we performed a comparative proteomic study to identify differentially expressed plasma proteins in various BD mood states (depressed BD, manic BD, and euthymic BD) relative to healthy controls. A total of 10 euthymic BD, 20 depressed BD, 15 manic BD, and 20 demographically matched healthy control subjects were recruited. Seven high-abundance proteins were immunodepleted in plasma samples from the 4 experimental groups, which were then subjected to proteome-wide expression profiling by two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight tandem mass spectrometry. Proteomic results were validated by immunoblotting and bioinformatically analyzed using MetaCore. From a total of 32 proteins identified with 1.5-fold changes in expression compared with healthy controls, 16 proteins were perturbed in BD independent of mood state, while 16 proteins were specifically associated with particular BD mood states. Two mood-independent differential proteins, apolipoprotein (Apo) A1 and Apo L1, suggest that BD pathophysiology may be associated with early perturbations in lipid metabolism. Moreover, down-regulation of one mood-dependent protein, carbonic anhydrase 1 (CA-1), suggests it may be involved in the pathophysiology of depressive episodes in BD. Thus, BD pathophysiology may be associated with early perturbations in lipid metabolism that are independent of mood state, while CA-1 may be involved in the pathophysiology of depressive episodes.

Ipsilateral hippocampal proteomics reveals mitochondrial antioxidative stress impairment in cortical-lesioned chronic mild stressed rats

In this study, a two-dimensional gel-based proteomic approach was applied to profile the protein alterations underlying the significant adverse effects from post-stroke depression (PSD). In view of the close association between left prefrontal cortical dysfunction and PSD, a PSD rat model was constructed through a left anterior cortical lesion followed by chronic mild stress (CMS) for three weeks. Through sucrose preference testing, PSD rats displayed depression-like behavior during the entire CMS period. In contrast, stroke rats displayed depression-like behavior in the first week post-stroke and recovered in the second week post-stroke. To investigate the PSD-induced protein expression changes, ipsilateral hippocampal protein expression in stroke, PSD, and control rats were comparatively analyzed. 46 differential proteins were identified, 22 of which were regulated in opposing directions by stroke and post-stroke stress. The majority of these 22 proteins were involved in neurogenesis, cytoskeletal remodeling, and energy metabolism. Additional proteins were functionally related to mitochondrial antioxidative stress systems. The differential proteins expressed in opposing directions by stroke and post-stroke stress may play a role in self-repair after adult brain lesions, suggesting that stroke induces self-repair mechanisms, while post-stoke stress mitigates them, in the rat hippocampus. Among these differential proteins dysregulated in opposing directions, three mitochondrial proteins involved in mitochondrial antioxidative stress - heat shock 70 kDa protein 9, peroxiredoxin-6, and prohibitin - were validated and may play an important role in stroke-injury self-repair and PSD-induced injury of hippocampal neurons. These findings offer new insight into deciphering the molecular mechanisms underpinning PSD&#039;s adverse effects on stroke recovery.

Bilateral repetitive transcranial magnetic stimulation for treatment-resistant depression: a systematic review and meta-analysis of randomized controlled trials

There has been concern regarding the use of controversial paradigms for repetitive transcranial magnetic stimulation (rTMS) to manage treatment-resistant depression (TRD). This meta-analysis assessed the efficacy of bilateral rTMS compared with unilateral and sham rTMS in patients with TRD. PubMed, Embase, CENTRAL, PsycINFO, Web of Science, EAGLE and NTIS databases were searched to identify relevant studies, and randomized controlled trials (RCTs) on bilateral rTMS for TRD patients were included. The response was defined as the primary outcome, and remission was the secondary outcome. Ten RCTs that included 634 patients met the eligibility criteria. The risk ratio (RRs) of both the primary and secondary outcomes of bilateral rTMS showed non-significant increases compared to unilateral rTMS (RR=1.01, P=0.93; odds ratio [OR]=0.77, P=0.22). Notably, the RR of the primary bilateral rTMS outcome was significantly increased compared to that for sham rTMS (RR=3.43, P=0.0004). The results of our analysis demonstrated that bilateral rTMS was significantly more effective than sham rTMS but not unilateral rTMS in patients with TRD. Thus, bilateral rTMS may not be a useful paradigm for patients with TRD.

The RBMX gene as a candidate for the Shashi X-linked intellectual disability syndrome

A novel X-linked intellectual disability (XLID) syndrome with moderate intellectual disability and distinguishing craniofacial dysmorphisms had been previously mapped to the Xq26-q27 interval. On whole exome sequencing in the large family originally reported with this disorder, we identified a 23 bp frameshift deletion in the RNA binding motif protein X-linked (RBMX) gene at Xq26 in the affected males (n = 7), one carrier female, absent in unaffected males (n = 2) and in control databases (7800 exomes). The RBMX gene has not been previously causal of human disease. We examined the genic intolerance scores for the coding regions and the non-coding regions of RBMX; the findings were indicative of RBMX being relatively intolerant to loss of function variants, a distinctive pattern seen in a subset of XLID genes. Prior expression and animal modeling studies indicate that loss of function of RBMX results in abnormal brain development. Our finding putatively adds a novel gene to the loci associated with XLID and may enable the identification of other individuals affected with this distinctive syndrome.