The management of ADHD and associated problems in a young person with cleidocranial dysostosis (CCD) and mild intellectual disability

A novel single-base deletion of the RUNX Family Transcription Factor 2 gene associated with cleidocranial dysplasia

Cleidocranial dysplasia (CCD) is a rare, autosomal dominant hereditary disorder characterized by skeletal malformations and dental abnormalities. The purpose of this study was to explore the functional role of a novel mutation in the pathogenesis of CCD. Genomic DNA was extracted from peripheral blood mononuclear cells collected from family members of a Chinese patient with CCD. An analysis of their RUNX Family Transcription Factor 2 (RUNX2) gene sequences was performed by PCR amplification and Sanger sequencing. The function of the mutant RUNX2 was studied by bioinformatics, real-time PCR, western blotting, and subcellular localization analysis. Sanger sequencing identified a novel single-base deletion (NM_001024630.4:c.132delG;NP_001019801.3: Val45Trpfs^* 99) in the RUNX2 gene present in the Chinese patient with CCD. In vitro, functional studies showed altered protein localization and increased expression of mutant RUNX2 mRNA and mutant Runt-related transcription factor 2 (RUNX2). Luciferase reporter assay demonstrated that the novel RUNX2 mutations significantly increased the transactivation activity of RUNX2 on the osteocalcin gene promoter. In conclusion, we identified a patient with sporadic CCD carrying a novel deletion/frameshift mutation of the RUNX2 gene and performed screening and functional analyses to determine the cause of the CCD phenotype. This study provides new insights into the pathogenesis of CCD.3.

Heterozygous pathogenic variants involving CBFB cause a new skeletal disorder resembling cleidocranial dysplasia

BACKGROUND

Cleidocranial dysplasia (CCD) is a rare skeletal dysplasia with significant clinical variability. Patients with CCD typically present with delayed closure of fontanels and cranial sutures, dental anomalies, clavicular hypoplasia or aplasia and short stature. Runt-related transcription factor 2 (RUNX2) is currently the only known disease-causing gene for CCD, but several studies have suggested locus heterogeneity.

METHODS

The cohort consists of eight subjects from five unrelated families partially identified through GeneMatcher. Exome or genome sequencing was applied and in two subjects the effect of the variant was investigated at RNA level.

RESULTS

In each subject a heterozygous pathogenic variant in CBFB was detected, whereas no genomic alteration involving RUNX2 was found. Three CBFB variants (one splice site alteration, one nonsense variant, one 2 bp duplication) were shown to result in a premature stop codon. A large intragenic deletion was found to delete exon 4, without affecting CBFB expression. The effect of a second splice site variant could not be determined but most likely results in a shortened or absent protein. Affected individuals showed similarities with RUNX2-related CCD, including dental and clavicular abnormalities. Normal stature and neurocognitive problems were however distinguishing features. CBFB encodes the core-binding factor β subunit, which can interact with all RUNX proteins (RUNX1, RUNX2, RUNX3) to form heterodimeric transcription factors. This may explain the phenotypic differences between CBFB-related and RUNX2-related CCD.

CONCLUSION

We confirm the previously suggested locus heterogeneity for CCD by identifying five pathogenic variants in CBFB in a cohort of eight individuals with clinical and radiographic features reminiscent of CCD.

Demographic, clinical, and radiological characteristics of cleidocranial dysplasia: A systematic review of cases reported in south America

Introduction

Cleidocranial dysplasia (CCD) is a rare disease characterized by craniofacial, skeletal, and oral anomalies. The disease prevalence is estimated to be 1 per million inhabitants; thus, only a few studies have described large cohorts of CCD patients. This study reviewed the clinical-radiological and demographic characteristics of patients with CCD in South America.

Methods

We conducted a systematic review of all cases of CCD reported in South America following the PRISMA guidelines. Demographic information (sex, age at diagnosis, origin, reason for consultation, and family history) was also recorded. CCD signs were divided into “craniofacial” and “skeletal” categories.

Results

A total of 72 cases were included. We found that oral anomalies were the most common reason for consultation leading to a diagnosis in patients, with a median age at diagnosis of 14 years. Fifty percent of the patients were women. Open fontanels or cranial sutures, the presence of at least one of the typical CCD facies (frontal bossing, brachycephaly, hypertelorism, or depression of the nasal bridge), and supernumerary teeth were reported in 92%, 85%, and 88% of cases, respectively. Clavicular dysplasia was present in 98.6% of cases, and other skeletal abnormalities such as scoliosis, pubic symphysis diastasis, and flat feet were found; short stature was present in 71% of cases, and one case presented cognitive deficits.

Conclusion

Although the phenotypic spectrum of CCD is variable, clavicular dysplasia, open fontanels or cranial sutures, dental anomalies, and at least one of the typical CCD facies are present in at least 80% of cases.

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About 70% of patients are diagnosed during childhood or adolescence, mostly due to dental complications.

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Clavicular dysplasia, open fontanel, dental abnormalities, and facies typical of CCD are present in at least 80% of cases.

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The prevalence of CCD signs in the South American population is similar to other patient groups from other populations.

Interaction of bone and brain: osteocalcin and cognition

INTRODUCTION

Bone has conventionally been considered to be a passive organ that only receives external control, but according to recent findings, it has become clear that bone is an endocrine organ that actively regulates systemic metabolism through osteocalcin (OC).

METHODS

We focus on the relationship between the brain and bone and summarize the effects of OC on cognitive function as well as the association between OC and improved cognitive function through exercise.

RESULTS

The findings suggest that the decrease in OC produced by bone is responsible for the decrease in cognitive function associated with aging. Furthermore, positive effect of improving cognitive function can generally be recognized in exercise interventions conducted for healthy elderly people and those with MCI, and moderate exercise is particularly effective for dementia prevention.

CONCLUSION

The improving bone health with aging may exert beneficial effects on cognition.

Delayed Eruption of Permanent Dentition and Maxillary Contraction in Patients with Cleidocranial Dysplasia: Review and Report of a Family

Introduction

Cleidocranial dysplasia (CCD) is an inherited disease caused by mutations in the RUNX2 gene on chromosome 6p21. This pathology, autosomal dominant or caused by a spontaneous genetic mutation, is present in one in one million individuals, with complete penetrance and widely variable expressivity.

Aim

To identify the incidence of these clinical findings in the report of the literature by means of PubMed interface from 2002 to 2015, with the related keywords. The report of local patients presents a clinical example, related to the therapeutic approach.

Results and Discussions

The PubMed research resulted in 122 articles. All the typical signs were reported in all presented cases. The maxilla was hypoplastic in 94% of the patients. Missing of permanent teeth was found in two cases: one case presented a class II jaw relationship, instead of class III malocclusion. Similar findings were present in our cohort.

Conclusion

CCD is challenging for both the dental team and the patient. The treatment requires a multidisciplinary approach. Further studies are required to better understand the cause of this disease. According to this review, a multistep approach enhances the possibilities to achieve the recovery of the most possible number of teeth, as such to obtain a good occlusion and a better aesthetic.

[Osteocalcin, a key molecule for bone endocrine functions]

The maintenance of our physiological functions and their adaptive response to environmental changes depend on precise crosstalk between organs. Recent advances in mouse genetics have helped demonstrate that this holistic view of physiology extends to the skeletal system, where many unexpected signaling axes are found to play essential roles affecting numerous organs. After being long regarded as a static tissue, functioning merely as a structural support system, the skeleton has seen its image evolve into a much more complex picture. The skeleton reveals itself as a key endocrine organ for the homeostasis of our body, both by its central position in our body, but also by the large number of physiological functions it influences. In this review, we discuss the multiple endocrine roles of osteocalcin, an osteoclast-derived molecule (Ocn), where its functional importance has steadily increased over the last 15 years.

Decreased serum undercarboxylated osteocalcin is associated with cognitive impairment in male patients with type 2 diabetes

BACKGROUND

Basic and clinical researches have suggested that type 2 diabetes (T2DM) is associated with cognitive impairment, and diabetes mellitus increases the risk of cognitive impairment and dementia. Recently, some reports found that undercarboxylated osteocalcin (ucOC) could affect brain functions, and decreased in patients with T2DM. We aimed to investigate the association of serum ucOC with cognitive impairment in T2DM patients.

METHODS

A total of 196 male T2DM patients without medications known to affect bone metabolism or history of bone fracture, aged ≥18years were recruited and divided into impaired cognition group and normal cognition group. We use the scores of Minimum Mental State Examination (MMSE) to evaluate the subjects' cognitive function. Detailed cognitive performance was also evaluated by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Serum ucOC was measured by Enzyme-Linked Immunosorbent Assay (ELISA) kit.

RESULTS

Compared to male T2DM patients with normal cognition, the mean osteocalcin concentrations were significantly lower in male T2DM patients with impaired cognition (P<0.05). RBANS total and all indexes scores were also lower in patients with impaired cognition (all P<0.05). After adjusted effects of confounding factors, serum ucOC was positively correlated with a variety indexes of RBANS except visuospatial/constructional.

CONCLUSIONS

The serum ucOC is positively correlated with RBANS scores in male T2DM patients. It suggests that serum ucOC may be involved in the development and progression of cognitive dysfunction in T2DM patients.

Analysis of serum undercarboxylated osteocalcin level in rats with type 2 diabetes mellitus and the correlation with cognitive impairment

The aim of the study was to investigate the correlation between the serum undercarboxylated osteocalcin (ucOC) level and the blood biochemistry and cognitive impairment in rats with type 2 diabetes mellitus (T2DM). Sprague-Dawley (SD) rats were randomly divided into the normal control group (NC) and type 2 DM group. DM group received the high-fat and high-sugar diet combined with the intraperitoneal injection of low-dose STZ to establish the type 2 DM rat model. After 12 weeks of feeding, a Morris water maze was used to observe the rats' cognitive ability, and the levels of blood lipid, ucOC, insulin and adiponectin in the two groups were measured. The results showed that blood glucose of rats in DM group was increased significantly at 2–12 weeks (p<0.01) and the body weight was significantly increased at 4–12 weeks (p<0.01). The levels of serum triglyceride (TG), total cholesterol, low-density lipoprotein and insulin in rats in DM group were significantly increased compared with those in NC group (p<0.01) and the levels of high-density lipoprotein, adiponectin and ucOC were significantly decreased compared with those in the NC group (p<0.01). The place navigation and spatial exploration capacities of rats in DM group were significantly decreased compared with those in NC group (p<0.01). In the DM group, the place navigation and spatial exploration capacities of rats in the low ucOC group were significantly decreased compared with those in the high ucOC group (p<0.01). Additionally, single-factor correlation analysis revealed that ucOC was negatively correlated with blood glucose, TG and escape latency (p<0.01), but was positively correlated with adiponectin, residence time in target quadrant and traversing times (p<0.05 or p<0.01). In conclusion, the decreased serum ucOC level in rats with type 2 diabetes mellitus has a certain correlation with cognitive impairment.

Lower serum osteocalcin concentrations are associated with brain microstructural changes and worse cognitive performance

OBJECTIVE

Rodent models have found that osteocalcin crosses the blood-brain barrier and regulates behaviour. No data are available on osteocalcin's effects on brain microstructure and cognitive performance in humans. We evaluated the association between serum osteocalcin concentrations and (i) brain microstructural changes on magnetic resonance imaging (MRI) and (ii) neuropsychological performance.

DESIGN, PATIENTS AND MEASUREMENTS

We studied 24 consecutive obese subjects (13 women; age, 49·8 ± 8·1 years; body mass index [BMI], 43·9 ± 4·54 kg/m(2) ) and 20 healthy volunteers (10 women; age, 48·8 ± 9·5 years; BMI, 24·3 ± 3·54 kg/m(2) ) in a cross-sectional study within the multicentre FLORINASH Project. FLAIR signal intensity and DTI-metrics (primary (λ1 ), secondary (λ2 ) and tertiary (λ3 ) eigenvalues; fractional anisotropy (FA); and mean diffusivity) in the caudate, hypothalamus, thalamus and putamen, and in subcortical white matter were assessed. Cognitive performance evaluated by neuropsychological test battery.

RESULTS

Lower osteocalcin concentrations were associated with BMI, higher λ1, λ2 and λ3 values at the caudate and lower FLAIR signal intensity at the caudate and putamen. Obese patients with lower osteocalcin concentrations had higher FA at putamen and thalamus. Lower osteocalcin concentrations were associated with higher Iowa Gambling Task (IGT) scores. FLAIR signal intensity at the caudate <601·832 yielded 85·7% sensitivity, 64·3% specificity, 70·6% negative predictive value and 81·8% positive predictive value for IGT score. Lower osteocalcin was an independent predictor of worse cognitive performance on multivariate analysis (F = 3·551, P = 0·01343; R(2) = 0·103). Bayesian information criterion demonstrated that osteocalcin had the predominant role in predicting IGT score.

CONCLUSIONS

Lower serum osteocalcin concentrations are associated with brain microstructural changes and worse cognitive performance.

Searching for additional endocrine functions of the skeleton: genetic approaches and implications for therapeutics

Our knowledge of whole organism physiology has greatly advanced in the past decades through mouse genetics. In particular, genetic studies have revealed that most organs interact with one another through hormones in order to maintain normal physiological functions and the homeostasis of the entire organism. Remarkably, through these studies many unexpected novel endocrine means to regulate physiological functions have been uncovered. The skeletal system is one example. In this article, we review a series of studies that over the years have identified bone as an endocrine organ. The mechanism of action, pathological relevance, and therapeutic implications of the functions of the bone-derived hormone osteocalcin are discussed. In the last part of this review we discuss the possibility that additional endocrine functions of the skeleton may exist.

Maternal and offspring pools of osteocalcin influence brain development and functions

The powerful regulation of bone mass exerted by the brain suggests the existence of bone-derived signals modulating this regulation or other functions of the brain. We show here that the osteoblast-derived hormone osteocalcin crosses the blood-brain barrier, binds to neurons of the brainstem, midbrain, and hippocampus, enhances the synthesis of monoamine neurotransmitters, inhibits GABA synthesis, prevents anxiety and depression, and favors learning and memory independently of its metabolic functions. In addition to these postnatal functions, maternal osteocalcin crosses the placenta during pregnancy and prevents neuronal apoptosis before embryos synthesize this hormone. As a result, the severity of the neuroanatomical defects and learning and memory deficits of Osteocalcin(-/-) mice is determined by the maternal genotype, and delivering osteocalcin to pregnant Osteocalcin(-/-) mothers rescues these abnormalities in their Osteocalcin(-/-) progeny. This study reveals that the skeleton via osteocalcin influences cognition and contributes to the maternal influence on fetal brain development.