Improvement of bone properties in children with osteogenesis imperfecta after pamidronate: a bone biopsy study.

OI, or bone brittle disease, is characterized by increased mineralization of bone matrix independently of clinical severity. So, a beneficial effect of antiresorptive treatments such as bisphosphonates (BP) is questionable. We aim to compare the bone matrix characteristics before and after BP pamidronate (PAM).

Aarskog-Scott syndrome: a clinical study based on a large series of 111 male patients with a pathogenic variant in and management recommendations.

Background: Aarskog-Scott syndrome (AAS) is a rare condition with multiple congenital anomalies, caused by hemizygote variants in the gene. Its description was based mostly on old case reports, in whom a molecular diagnosis was not always available, or on small series. The aim of this study was to better delineate the phenotype and the natural history of AAS and to provide clues for the diagnosis and the management of the patients.

SLC10A7 regulates O-GalNAc glycosylation and Ca homeostasis in the secretory pathway: insights into SLC10A7-CDG.

Glycans are known to be fundamental for many cellular and physiological functions. Congenital disorders of glycosylation (CDG) currently encompassing over 160 subtypes, are characterized by glycan synthesis and/or processing defects. Despite the increasing number of CDG patients, therapeutic options remain very limited as our knowledge on glycan synthesis is fragmented.

International consensus guidelines on the implementation and monitoring of vosoritide therapy in individuals with achondroplasia.

Achondroplasia is the most common genetic form of short-limbed skeletal dysplasia (dwarfism). Clinical manifestations and complications can affect individuals across the lifespan, including the need for adaptations for activities of daily living, which can affect quality of life. Current international guidelines focus on symptomatic management, with little discussion regarding potential medication, as therapeutic options were limited at the time of their publication.

Next Generation Phenotyping and Synthetic Faces in Coffin Siris Syndrome.

Diagnostic wandering and delayed management are major issues in rare diseases. Here, we report a new Next-Generation Phenotyping (NGP) model for diagnosing Coffin Siris syndrome (CSS) on clinical photographs among controls and distinguish the different genotypes. This retrospective and prospective study, conducted from 1998 to 2023, included frontal and lateral pictures of confirmed CSS.

Loss-of-function of DDR1 is responsible for a chondrodysplasia with multiple dislocations.

Chondrodysplasias with multiple dislocations are rare skeletal disorders characterized by hyperlaxity, joint dislocations, and growth retardation. Chondrodysplasias with multiple dislocations have been linked to pathogenic variants in genes encoding proteins involved in the proteoglycan biosynthesis. In this study, by exome sequencing analysis, we identified a homozygous nonsense variant (NM_001297654.

Foetal achondroplasia: Prenatal diagnosis, outcome and perspectives.

Background: Achondroplasia, due to a specific pathogenic variant in FGFR3, is the most common viable skeletal dysplasia and the diagnosis is mostly done in the prenatal period. Since 2021, the use of Vosoritide, a specific treatment for achondroplasia, validated in phase 3 placebo-controlled trials, has been recommended to significantly increase the height of children and infants. In the light of these new therapeutic prospects, a complete understanding of the pathophysiology of skeletal damages occurring from foetal life is required.

Genetic variability in proteoglycan biosynthetic genes reveals new facets of heparan sulfate diversity.

Heparan sulfate (HS) and chondroitin sulfate (CS) proteoglycans (PG) consist of a core protein to which the glycosaminoglycan (GAG) chains, HS or CS, are attached through a common linker tetrasaccharide. In the extracellular space, they are involved in the regulation of cell communication, assuring development and homeostasis. The HSPG biosynthetic pathway has documented 51 genes, with many diseases associated to defects in some of them.

Evidence for therapeutic use of cannabidiol for nail-patella syndrome-induced pain in a real-world pilot study.

Nail-patella syndrome (NPS) is a rare genetic disease characterized by dysplastic nails, patella abnormalities, skeletal malformation, and chronic pain. Although chronic pain in NPS is mainly due to bone and musculoskeletal symptoms, it can also result from neurological dysfunction. Conventional analgesics are often insufficient to relieve NPS-associated chronic pain.

Regulated N-glycosylation controls chaperone function and receptor trafficking.

One-fifth of human proteins are N-glycosylated in the endoplasmic reticulum (ER) by two oligosaccharyltransferases, OST-A and OST-B. Contrary to the prevailing view of N-glycosylation as a housekeeping function, we identified an ER pathway that modulates the activity of OST-A. Genetic analyses linked OST-A to HSP90B1, an ER chaperone for membrane receptors, and CCDC134, an ER luminal protein.

Osteogenesis Imperfecta: A study of the patient journey in 13 European countries.

Introduction: Osteogenesis imperfecta (OI) is a heritable skeletal disorder and comprises various subtypes that differ in clinical presentation, with Type I considered the least severe and Types III/IV the most severe forms. The study aim was to understand the OI patient diagnostic and treatment journey across Europe.

Methods: We conducted a qualitative, descriptive study to understand the OI patient journey.

The unfolded protein response regulates ER exit sites via SNRPB-dependent RNA splicing and contributes to bone development.

Splicing and endoplasmic reticulum (ER)-proteostasis are two key processes that ultimately regulate the functional proteins that are produced by a cell. However, the extent to which these processes interact remains poorly understood. Here, we identify SNRPB and other components of the Sm-ring, as targets of the unfolded protein response and novel regulators of export from the ER.

SMAD4 mutations causing Myhre syndrome are under positive selection in the male germline.

While it is widely thought that de novo mutations (DNMs) occur randomly, we previously showed that some DNMs are enriched because they are positively selected in the testes of aging men. These "selfish" mutations cause disorders with a shared presentation of features, including exclusive paternal origin, significant increase of the father's age, and high apparent germline mutation rate. To date, all known selfish mutations cluster within the components of the RTK-RAS-MAPK signaling pathway, a critical modulator of testicular homeostasis.

Myhre syndrome in adulthood: clinical variability and emerging genotype-phenotype correlations.

Myhre syndrome (MS, MIM 139210) is a rare multisystemic disorder caused by recurrent pathogenic missense variants in SMAD4. The clinical features have been mainly documented in childhood and comprise variable neurocognitive development, recognizable craniofacial features, a short stature with a pseudo-muscular build, hearing loss, thickened skin, joint limitations, diverse cardiovascular and airway manifestations, and increased fibrosis often following trauma or surgery. In contrast, adults with MS are underreported obscuring potential clinical variability.

Clinical spectrum of rare bone fragility disorders and response to bisphosphonate treatment: a retrospective study.

Osteogenesis Imperfecta (OI) is a clinically and genetically heterogeneous group of diseases characterized by brittle bones. Though genetic mutations in COL1A1 and COL1A2 account for approximately 85-90% of OI cases, there are now more than twenty genes described, responsible for rare forms of OI. Treatment is based on the use of bisphosphonates and though it is well established that they increase lumbar spine (LS) bone mineral density (BMD), the clinical impact on fracture reduction is still debated.

European Achondroplasia Forum Practical Considerations for Following Adults with Achondroplasia.

Achondroplasia is a lifelong condition requiring lifelong management. There is consensus that infants and children with achondroplasia should be managed by a multidisciplinary team experienced in the condition. However, many people are lost to follow-up after the transition from paediatric to adult care, and there is no standardised approach for management in adults, despite the recent availability of international consensus guidelines.

Root resorptions induced by genetic disorders: A systematic review.

Objectives: Root resorption in permanent teeth is a common pathological process that often follows dental trauma or orthodontic treatment. More rarely, root resorption is a feature of genetic disorders and can help with diagnosis. Thus, the present review aims to determine which genetic disorders could induce pathological root resorptions and thus which mutated genes could be associated with them.