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Rubinstein-Taybi syndrome (RTS) is an archetypical genetic syndrome that is characterised by intellectual disability, well-defined facial features, distal limb anomalies and atypical growth, among numerous other signs and symptoms. It is caused by variants in either of two genes ( CREBBP , EP300 ) which encode for the proteins CBP and p300, which both have a function in transcription regulation and histone acetylation. As a group of international experts and national support groups dedicated to the syndrome, we realised that marked heterogeneity currently exists in clinical and molecular diagnostic approaches and care practices in various parts of the world. Here, we outline a series of recommendations that document the consensus of a group of international experts on clinical diagnostic criteria for types of RTS (RTS1: CREBBP ; RTS2: EP300 ), molecular investigations, long-term management of various particular physical and behavioural issues and care planning. The recommendations as presented here will need to be evaluated for improvements to allow for continued optimisation of diagnostics and care., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Rubinstein-Taybi syndrome (RSTS) is an extremely rare autosomal dominant genetic disease, with an estimated prevalence of one case per 125,000 live births. RSTS is characterized by typical facial features, microcephaly, broad thumbs and first toes, intellectual disability, and postnatal growth retardation. However, no standard diagnostic criteria are available for RSTS. In this review, we summarized the clinical features and genetic basis of RSTS and highlighted areas for future studies on an appropriate diagnostic protocol and follow-up care for RSTS., Discussion: RSTS is primarily characterized by delayed growth in height and weight, microcephaly, dysmorphic facial features, and broad thumbs and big toe. Over 90% RSTS individuals with disabilities survive to adulthood, but healthcare for these patients is particularly complex, time-consuming, and costly. In addition, no standard diagnostic criteria and follow-up care guidelines are available for RSTS. It has been shown that mutations in the genes encoding the cyclic-AMP-regulated enhancer binding protein (CREBBP) and the E1A-binding protein p300 (EP300) contributed to the development of RSTS. Therefore, genetic tests are useful for the diagnosis of RSTS, although most RSTS cases are currently diagnosed based on clinical features. The clinical features of RSTS have been extensively studied, which significantly contributes to the diagnosis of this extremely rare syndrome. However, the pathogenesis and genotype-phenotype associations of RSTS are largely unknown. Therefore, multicenter studies and international cooperation are highlighted for better understanding of this disease, establishing standard diagnostic criteria, and providing professional management and follow-up care of RSTS.

Mutations in the coactivator CREB-binding protein (CBP) are a major cause of the human skeletal dysplasia Rubinstein-Taybi syndrome (RTS); however, the mechanism by which these mutations affect skeletal mineralization and patterning is unknown. Here, we report the identification of 3-phosphoinositide-dependent kinase 1 (PDK1) as a key regulator of CBP activity and demonstrate that its functions map to both osteoprogenitor cells and mature osteoblasts. In osteoblasts, PDK1 activated the CREB/CBP complex, which in turn controlled runt-related transcription factor 2 (RUNX2) activation and expression of bone morphogenetic protein 2 (BMP2). These pathways also operated in vivo, as evidenced by recapitulation of RTS spectrum phenotypes with osteoblast-specific Pdk1 deletion in mice (Pdk1osx mice) and by the genetic interactions observed in mice heterozygous for both osteoblast-specific Pdk1 deletion and either Runx2 or Creb deletion. Finally, treatment of Pdk1osx and Cbp+/- embryos with BMPs in utero partially reversed their skeletal anomalies at birth. These findings illustrate the in vivo function of the PDK1-AKT-CREB/CBP pathway in bone formation and provide proof of principle for in utero growth factor supplementation as a potential therapy for skeletal dysplasias.

The Rubinstein-Taybi syndrome (broad thumb-hallux syndrome) is a rare congenital disease with prevalence 1:125,000 of life-born children. It is characterised by multiplex malformations, which includes growth and psychomotor retardation. Up to this date, over 1000 cases have been described in literature. This review is mainly focused on a description of symptoms, which occur in the syndrome mentioned above and serve as main diagnostic markers. Mutations in the CBP and the p300 genes have been associated with this disease as well. Therefore, substantial part is devoted to aetiology, where emphasis is put on a genetic origin of the Rubinstein-Taybi syndrome. Possibilities of this diagnose are mentioned at the end of the article.

In this review a short overview of pertinent clinical and molecular data of the Rubinstein-Taybi syndrome are provided. A diagnostic decision algorithm, and major issues that should be considered in the management of patients are discussed. Suggestions for further research are given.

Rubinstein-Taybi syndrome (RTS), also known as 'broad thumbs syndrome' or 'broad thumb-hallux syndrome', is a malformation syndrome characterized by the triad of broad thumbs or first toes, a peculiar facial expression called 'comical face' and mental retardation. Although various malformations are combined with the triad, polydactyly is rare. We treated a male patient with RTS complicated by postaxial polydactyly of the foot. His clinical course was different from typical patients with polydactyly, especially in the aspect of walking development. Osteoplasty-combined surgery, which was ideal for anatomical reconstruction, was performed on the patient at 2 years and 11 months of age. A 4-year follow-up period was required until there was an improvement of dysbasia.

Children and adults with Rubinstein-Taybi Syndrome have specific medical conditions that occur with greater frequency than the general population. Based on the available information from the literature and clinical experience, recommendations for specific surveillance and interventions are made to guide those clinicians caring for individuals with Rubinstein-Taybi Syndrome. This is a first attempt at medical guidelines for individuals with RTS in the United States. On-going research is needed in many areas to guide decisions in medical care and allow for refinement of these medical guidelines., (Copyright 2003 Wiley-Liss, Inc.)

The authors described symptoms of Rubinstein-Taybi syndrome and presented a treatment of this disease. It concerned a 1-year-old baby with obstruction of left lacrimal ducts, psychomotor retardation and facial abnormalities.

Behavioral characteristics of three children with Broad Thumb-Hallux or Rubinstein-Taybi (R-T) syndrome were compared with those of a somewhat comparable clinic sample (N - 15) of children with organic syndromes and retardation. A number of mutual, behavioral resemblances of the three R-T children to each other were found to be absent or less prominent in the comparison group; these included: (i) the R-T children were more emotional and excitable; (ii) more often had nightmares and engaged in self-stimulation; (iii) had greater difficulty getting over anger (pouted); (iv) were friendly and more readily accepted social contacts; (v) had short attention span; and (vi) experienced more difficulty in planning motor acts, and in executing locomotor and oculomotor skills. The pattern of R-T mutual resemblances and their differences from other clinic children logically suggest what may be the behavioral characteristics of children with the R-T syndrome. Educational and child-management suggestions are provided based on the observed and tested characteristics which are presumably related to the R-T syndrome.