Haploinsufficiency of the GPD2 gene in a patient with nonsyndromic mental retardation

We have investigated the chromosome abnormalities in a female patient exhibiting mild nonsyndromic mental retardation. The patient carries a de novo balanced reciprocal translocation 46,XX,t(2;7)(q24.1;q36.1). Physical mapping of the breakpoints by fluorescent in situ hybridization experiments revealed the disruption of the GPD2 gene at the 2q24.1 region. This gene encodes the mitochondrial glycerophosphate dehydrogenase (mGPDH), which is located on the outer surface of the inner mitochondrial membrane, and catalyzes the unidirectional conversion of glycerol-3-phosphate (G3P) to dihydroxyacetone phosphate with concomitant reduction of the enzyme-bound FAD. Molecular and functional studies showed approximately a twofold decrease of GPD2 transcript level as well as decreased activity of the coded mGPDH protein in lymphoblastoid cell lines of the patient compared to controls. Bioinformatics analysis allowed us to confirm the existence of a novel transcript of the GPD2 gene, designated GPD2c, which is directly disrupted by the 2q breakpoint. To validate GPD2 as a new candidate gene for mental retardation, we performed mutation screening of the GPD2 gene in 100 mentally retarded patients; however, no mutations have been identified. Nevertheless, our results propose that a functional defect of the mGPDH protein could be associated with mental retardation, suggesting that GPD2 gene could be involved in mental retardation in some cases.

Positive Effect of Visual Cuing in Episodic Memory and Episodic Future Thinking in Adolescents With Autism Spectrum Disorder

Cognitive studies generally report impaired autobiographical memory in individuals with autism spectrum disorder (ASD), but mostly using verbal paradigms. In the present study, we therefore investigated the properties of both past and future autobiographical productions using visual cues in 16 boys with ASD and 16 typically developing (TD) participants aged between 10 and 18 years. We focused on sensory properties, emotional properties, and recollection, probing past and future productions for both near and distant time periods. Results showed that the ASD group performed more poorly than controls on free recall for recent periods, but performed like them when provided with visual cues. In addition, the ASD group reported fewer sensory details than controls and exhibited difficulties in the experience of recollection for the most remote events. These data suggest a combination of consolidation and binding deficits. Finally, our findings reveal the relevance of using visual cues to probe autobiographical memory, with possible perspectives for memory rehabilitation.

Brain correlates of declarative memory atypicalities in autism: a systematic review of functional neuroimaging findings

The long-described atypicalities of memory functioning experienced by people with autism have major implications for daily living, academic learning, as well as cognitive remediation. Though behavioral studies have identified a robust profile of memory strengths and weaknesses in autism spectrum disorder (ASD), few works have attempted to establish a synthesis concerning their neural bases. In this systematic review of functional neuroimaging studies, we highlight functional brain asymmetries in three anatomical planes during memory processing between individuals with ASD and typical development. These asymmetries consist of greater activity of the left hemisphere than the right in ASD participants, of posterior brain regions-including hippocampus-rather than anterior ones, and presumably of the ventral (occipito-temporal) streams rather than the dorsal (occipito-parietal) ones. These functional alterations may be linked to atypical memory processes in ASD, including the pre-eminence of verbal over spatial information, impaired active maintenance in working memory, and preserved relational memory despite poor context processing in episodic memory.

[Preventing carer burnout]

The issue of the burnout of carers of disabled family members has been raising concern for several years. It is essential to identify the signs of suffering in the carer in order to put in place adapted support which will also be beneficial for the person being cared for. Autism, a disability which has a significant impact on the family circle, is an example of a condition for which providing support to carers is essential.

Local Processing Bias Impacts Implicit and Explicit Memory in Autism

Autism spectrum disorder (ASD) is characterized by atypical perception, including processing that is biased toward local details rather than global configurations. This bias may impact on memory. The present study examined the effect of this perception on both implicit (Experiment 1) and explicit (Experiment 2) memory in conditions that promote either local or global processing. The first experiment consisted of an object identification priming task using two distinct encoding conditions: one favoring local processing (Local condition) and the other favoring global processing (Global condition) of drawings. The second experiment focused on episodic (explicit) memory with two different cartoon recognition tasks that favored either local (i.e., processing specific details) or a global processing (i.e., processing each cartoon as a whole). In addition, all the participants underwent a general clinical cognitive assessment aimed at documenting their cognitive profile and enabling correlational analyses with experimental memory tasks. Seventeen participants with ASD and 17 typically developing (TD) controls aged from 10 to 16 years participated to the first experiment and 13 ASD matched with 13 TD participants were included for the second experiment. Experiment 1 confirmed the preservation of priming effects in ASD but, unlike the Comparison group, the ASD group did not increase his performance as controls after a globally oriented processing. Experiment 2 revealed that local processing led to difficulties in discriminating lures from targets in a recognition task when both lures and targets shared common details. The correlation analysis revealed that these difficulties were associated with processing speed and inhibition. These preliminary results suggest that natural perceptual processes oriented toward local information in ASD may impact upon their implicit memory by preventing globally oriented processing in time-limited conditions and induce confusion between explicit memories that share common details.

[Supporting parents during disclosure of a child's disability]

Parents of disabled children often describe the disclosure of their child's diagnosis as a traumatic experience. The quality of support provided to family members at the time of disclosure helps alleviate their suffering and improve their resilience. With better insight into the psychological processes involved, healthcare professionals can ensure proper supportive care in each situation.

[Mandibular osteitis on a periapical granuloma mimicking an osteosarcoma: a case report]

INTRODUCTION

Osteitis is an inflammatory disease of bone tissue. Its clinical presentation varies according to the site, presence or absence of pus, duration and etiology. It represents one of the endo-periodontal diseases complication. We report the case of a mandibular osteitis having led to confusion with an ostesarcoma.

OBSERVATION

A 13-year-old boy was referred to our department for a right low swelling with suspicion of mandible osteosarcoma. The lesion’s evolution was 6 weeks. With the local aggressiveness and the speed evolution, the first diagnosis proposed was a mandibular osteosarcoma. Based on the clinical and radiological data established, the diagnosis of mandibular osteitis on a periapical granuloma was made and the treatment consisted on the causal tooth extraction with curettage of the periapical lesion associated to the prescription of macrolide (ERY®). The clinical follow-up was 6 weeks, a recovery with cessation of clinical signs were noticed.

DISCUSSION

The differential diagnosis facing the clinical context is an osteitis on a periapical inflammatory cyst and especially mandibular osteosarcoma. For the therapy, it’s a 3 components treatment (etiology, medical and surgical) to obtain a recovery.