Natural history of 39 patients with Achondroplasia

Review of patients with achondroplasia: a single-center's experience with follow-up and associated morbidities

Achondroplasia (ACH; MIM #100,800), caused by a heterozygous gain of function pathogenic variant in the fibroblast growth factor receptor 3 gene (FGFR3; MIM*134,934), is the most prevalent and most readily identifiable cause of disproportionate short stature that is compatible with life. In addition, individuals with achondroplasia face significant medical, functional, and psychosocial challenges throughout their lives. This study assessed associated morbidities in patients with achondroplasia at a single center in Turkey. In this study, the clinical findings and associated morbidities of a group of patients with achondroplasia (n = 68) with clinical multidisciplinary follow-up at a single center between the years 2005-2023 are evaluated retrospectively. A total of 68 patients, 30 male (44.1%) and 38 female (55.9%), were evaluated. In the majority (84.2%) of patients, shortness of extremities was detected in the prenatal period at an average of 28.7 gestational weeks (± 3.6 SDS) with the aid of ultrasonography. More than half (n = 34/63, 54%) of the patients had a father of advanced paternal age (≥ 35 years). Among the complications, respiratory system manifestations, including obstructive sleep apnea (70%), ear-nose-throat manifestations including adenoid hypertrophy (56.6%) and otitis media (54.7%), neurological manifestations due to foramen magnum stenosis (53.2%), and skeletal manifestations including scoliosis (28.8%), are represented among the most common. The mortality rate was 7.3% (n = 5/68).Conclusion: This study not only represents the first retrospective analysis of the associated morbidities of patients with achondroplasia from a single center in Turkey but also will provide a reference point for future studies.

Evaluation of functionality-mobility in patients with skeletal dysplasias. Application of the STEMS tool ("everyday symptoms and mobility screening tool for skeletal dysplasias")

Individuals with differing forms of skeletal dysplasias (SD) frequently report impaired mobility and symptoms. With the objetive to evaluate mobility and associated symptoms in people with SD at an Argentinian pediatric hospital, using an Argentinian version of the Screening Tool for Everyday Mobility and Symptoms (STEMS), a simple questionnaire that allows clinicians to quickly identify the presence of symptoms associated with mobility in people with SD, while considering different environmental settings and the use of assistive devices, an analytical study of a consecutive sample of patients older than 5 years with SD and their affected relatives was carried out.Diagnosis, comorbidities, socioenvironmental, therapeutic, auxological and mobility variables were recorded. The presence and intensity of symptoms was noted through use of both the STEMS and validated scales. Descriptive, association and correlation analyzes were performed. One hundred and nineteen individuals with SD were enrolled in the study and divided into groups: Osteogenesis Imperfecta (OI, n = 55), Achondroplasia (ACH, n = 36) and Other SD resulting in disproportionate short stature (n = 28). Mobility assistive devices were almost exclusively used by individuals with OI. They were more frequently used by individuals with overweight and obesity, more severe form of the disease and in the outdoor settings. Two thirds (66.4%) of the individuals assessed in this study reported pain, 87.4% reported fatigue, and 58.8% reported both pain and fatigue. The intensity of symptoms was similar between groups and correlated with age and auxological variables. The STEMS was clear, easy and quick to use for identifying presence of pain and fatigue in this population group. The STEMS proved to be a simple and useful tool for evaluating functional mobility and associated symptoms in our population of individuals with SD.

The clinical management of children with achondroplasia in Italy: results of clinician and parent/caregiver surveys

PURPOSE

This study aimed to assess the real-world management of achondroplasia in Italy.

METHODS

Two online surveys addressed to (1) parents/caregivers of individuals with achondroplasia and (2) Italian clinicians managing individuals with achondroplasia were conducted to assess real-world perspectives on achondroplasia management. Both surveys collected data on either patient or clinician demographics, details on diagnoses and referrals, disease complications, and views/experiences with limb lengthening surgery.

RESULTS

In total, 42 parents/caregivers and 19 clinicians (from 18 hospitals) completed the surveys. According to parents/caregivers, achondroplasia diagnosis was most commonly made in the third trimester of gestation (55% of respondents), with a genetic test performed to confirm the diagnosis in all but one case. In contrast, the clinicians indicated that, while achondroplasia was typically suspected during the prenatal period (78%), diagnosis was more frequently confirmed postnatally (72%). Parents/caregivers reported that the greatest impact of achondroplasia-related complications occurred in their children between the ages of 2-5 years. The most significant complications were otitis, sleep apnoea, stenosis of the foramen magnum or pressure on the spinal cord, and hearing difficulties. Lengthening surgery had been presented as a treatment option to 92% of responding parents/caregivers, with 76% of clinicians viewing surgery favourably. Typically, clinicians' reasons for suggesting limb lengthening surgery were to improve patient quality of life, increase patient autonomy and self-acceptance, improve trunk-limb disproportion, short stature and walking, and ensure that all possible treatment options had been presented to the parents/caregivers.

CONCLUSION

This survey provides insight into the real-world management of individuals with achondroplasia in Italy.

Review of published 467 achondroplasia patients: clinical and mutational spectrum

AIM

Achondroplasia is the most common of the skeletal dysplasias that cause fatal and disabling growth and developmental disorders in children, and is caused by a mutation in the fibroblast growth factor receptor, type 3 gene(FGFR3). This study aims to analyse the clinical characteristics and gene mutations of ACH to accurately determine whether a patient has ACH and to raise public awareness of the disease.

METHODS

The database of Pubmed, Cochrane Library, Wanfang and CNKI were searched with terms of "Achondroplasias" or "Skeleton-Skin-Brain Syndrome" or "Skeleton Skin Brain Syndrome" or "ACH" and "Receptor, Fibroblast Growth Factor, Type 3" or "FGFR3".

RESULTS

Finally, four hundred and sixty-seven patients with different FGFR3 mutations were enrolled. Of the 138 patients with available gender information, 55(55/138, 40%) were female and 83(83/138, 60%) were male. Among the patients with available family history, 47(47/385, 12%) had a family history and 338(338/385, 88%) patients were sporadic. The age of the patients ranged from newborn babies to 36 years old. The mean age of their fathers was 37 ± 7 years (range 31-53 years). Patients came from 12 countries and 2 continents, with the majority being Asian (383/432, 89%), followed by European (49/432, 11%). Short stature with shortened arms and legs was found in 112(112/112) patients, the abnormalities of macrocephaly in 94(94/112) patients, frontal bossing in 89(89/112) patients, genu valgum in 64(64/112) patients and trident hand were found in 51(51/112) patients. The most common mutation was p.Gly380Arg of the FGFR3 gene, which contained two different base changes, c.1138G > A and c.1138G > C. Ten rare pathogenic mutations were found, including c.831A > C, c.1031C > G, c.1043C > G, c.375G > T, c.1133A > G, c.1130T > G, c.833A > G, c.649A > T, c.1180A > T and c.970_971insTCTCCT.

CONCLUSION

ACH was caused by FGFR3 gene mutation, and c.1138G > A was the most common mutation type. This study demonstrates the feasibility of molecular genetic testing for the early detection of ACH in adolescents with short stature, trident hand, frontal bossing, macrocephaly and genu valgum.

Anesthetic management of parturients with achondroplasia: a case series

Background

Achondroplasia is the most common form of dwarfism, and cesarean delivery is often required in parturients with achondroplasia due to cephalopelvic disproportion. Given the challenges for both regional and general anesthetic techniques, there is no consensus on the optimal anesthetic management for cesarean delivery in these patients.

Method

A search of our electronic medical records for all female patients who had a diagnosis of achondroplasia and had a delivery in our health system from January 1, 2001 through June 16, 2023 was performed. Institutional review board exemption was obtained.

Results

We identified seven achondroplastic patients with 12 cesarean deliveries and described their anesthetic management during labor and delivery.

Conclusion

Despite the historical preference of general anesthesia in achondroplastic patients due to concerns of unpredictable spinal anatomy and unreliable local anesthetic spread, neuraxial anesthesia was successfully utilized in achondroplastic parturients and is a viable option in carefully selected patients. Reduction of intrathecal local anesthetic dose that minimizes the risk of high spinal and emergent intubation, as well as a titratable neuraxial technique, can be effective in this patient population.

How pain affect real life of children and adults with achondroplasia: A systematic review

The clinical features of achondroplasia can cause acute self-limited pain that can evolve into chronic pain. Pain causes a low quality of life, in terms of physical, emotional, social, and school functioning in both adult and children with achondroplasia. We conducted a systematic review according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement to describe prevalence, assessment tools, causes and management strategies of pain in this rare disease. We found that shoulder and knee pain is typically referred during infancy, while knee pain is generally referred around 5-6 years of age. The prevalence of general pain in adolescence can be as high as 90%. Chronic pain in the achondroplasia population increases with age, with up to 70% of adults reporting general pain and back pain. Recognizing the multiple determinants of acute and chronic pain in patients with achondroplasia may enable physicians to better understand and manage this burden, particularly with the advent of new drugs that may modify some of the striking features of achondroplasia.

A scoping review of nutrition issues and management strategies in individuals with skeletal dysplasia

PURPOSE

Skeletal dysplasia are heterogeneous conditions affecting the skeleton. Common nutrition issues include feeding difficulties, obesity, and metabolic complications. This systematic scoping review aimed to identify key nutrition issues, management strategies, and gaps in knowledge regarding nutrition in skeletal dysplasia.

METHODS

The databases Ovid MEDLINE, Ovid EMBASE, Ebsco CINAHL, Scopus, and Cochrane Central Register of Controlled Trials and Database of Systematic Reviews were searched. Reference lists and citing literature for included studies were searched. Eligible studies included participants with skeletal dysplasia and described: anthropometry, body composition, nutrition-related biochemistry, clinical issues, dietary intake, measured energy or nutrition requirements, or nutrition interventions.

RESULTS

The literature search identified 8509 references from which 138 studies were included (130 observational, 3 intervention, 2 systematic reviews, and 3 clinical guidelines). Across 17 diagnoses identified, most studies described osteogenesis imperfecta (n = 50) and achondroplasia or hypochondroplasia (n = 47). Nutrition-related clinical issues, biochemistry, obesity, and metabolic complications were most commonly reported, and few studies measured energy requirements (n = 5).

CONCLUSION

Nutrition-related comorbidities are documented in skeletal dysplasia; yet, evidence to guide management is scarce. Evidence describing nutrition in rarer skeletal dysplasia conditions is lacking. Advances in skeletal dysplasia nutrition knowledge is needed to optimize broader health outcomes.

Australian guidelines for the management of children with achondroplasia

Achondroplasia is the most common form of skeletal dysplasia. In addition to altered growth, children and young people with achondroplasia may experience medical complications, develop and function differently to others and require psychosocial support. International, European and American consensus guidelines have been developed for the management of achondroplasia. The Australian focused guidelines presented here are designed to complement those existing guidelines. They aim to provide core care recommendations for families and clinicians, consolidate key resources for the management of children with achondroplasia, facilitate communication between specialist, local teams and families and support delivery of high-quality care regardless of setting and geographical location. The guidelines include a series of consensus statements, developed using a modified Delphi process. These statements are supported by the best available evidence assessed using the National Health and Medicine Research Council's criteria for Level of Evidence and their Grading of Recommendations Assessment, Development and Evaluation (GRADE). Additionally, age specific guides are presented that focus on the key domains of growth, medical, development, psychosocial and community. The guidelines are intended for use by health professionals and children and young people with achondroplasia and their families living in Australia.

Associated anomalies in cases with achondroplasia

Associated congenital anomalies may be observed in cases with achondroplasia. The prevalence reported in the literature and the types of co-occurring congenital anomalies are variable between the reported studies. The aim of this study was to establish the prevalence and to describe the associated anomalies in cases with achondroplasia. This study included 25 cases ascertained from our registry of congenital anomalies including all terminations of pregnancy, stillbirths and live births between 1979 and 2007 in 387,067 consecutive births (the prevalence of achondroplasia was 6.4 per 100,000 births), and 223 cases ascertained from the French Little People organization built on the model of LPA (Little People of America, Inc.). Out of these 248 cases of achondroplasia 37 (14.9%) had associated anomalies including 4 (1.6%) cases with chromosomal abnormalities (2 trisomies 21, one 22 q11.2 deletion, and one 47, XXX), 2 (0.8%) cases with recognizable non-chromosomal conditions (one Moebius syndrome and one Pierre Robin sequence) and 31(12.5%) cases with MCA (multiple congenital anomalies). The 31 cases with MCA had 45 anomalies. Anomalies in the urogenital system (24.4%), the cardiovascular system (20.0%), the musculoskeletal system (15.5%), the central nervous system (11.1%), the eye (11.1%), and the orofacial system (8.8%) were the most common MCA. The overall prevalence of associated anomalies shows that the individuals with achondroplasia need a careful screening for other congenital anomalies.

Achondroplasia in Latin America: practical recommendations for the multidisciplinary care of pediatric patients

Background

Achondroplasia is the most common bone dysplasia associated with disproportionate short stature, and other comorbidities, such as foramen magnum stenosis, thoracolumbar kyphosis, lumbar hyperlordosis, genu varum and spinal compression. Additionally, patients affected with this condition have higher frequency of sleep disorders, ear infections, hearing loss and slowed development milestones. Considering these clinical features, we aimed to summarize the regional experts’ recommendations for the multidisciplinary management of patients with achondroplasia in Latin America, a vast geographic territory with multicultural characteristics and with socio-economical differences of developing countries.

Methods

Latin American experts (from Argentina, Brazil, Chile and Colombia) particiáted of an Advisory Board meeting (October 2019), and had a structured discussion how patients with achondroplasia are followed in their healthcare centers and punctuated gaps and opportunities for regional improvement in the management of achondroplasia.

Results

Practical recommendations have been established for genetic counselling, prenatal diagnosis and planning of delivery in patients with achondroplasia. An outline of strategies was added as follow-up guidelines to specialists according to patient developmental phases, amongst them neurologic, orthopedic, otorhinolaryngologic, nutritional and anthropometric aspects, and related to development milestones. Additionally, the role of physical therapy, physical activity, phonoaudiology and other care related to the quality of life of patients and their families were discussed. Preoperative recommendations to patients with achondroplasia were also included.

Conclusions

This study summarized the main expert recommendations for the health care professionals management of achondroplasia in Latin America, reinforcing that achondroplasia-associated comorbidities are not limited to orthopedic concerns.

[Clinical features and FGFR3 mutations of children with achondroplasia]

OBJECTIVES

To study the clinical features and fibroblast growth factor receptor 3 (FGFR3) gene mutations of children with achondroplasia (ACH) through an analysis of 17 cases.

METHODS

A retrospective analysis was performed on the clinical data and FGFR3 gene detection results of 17 children with ACH who were diagnosed from January 2009 to October 2021.

RESULTS

Of the 17 children with ACH, common clinical manifestations included disproportionate short stature (100%, 17/17), macrocephaly (100%, 17/17), trident hand (82%, 14/17), and genu varum (88%, 15/17). The common imaging findings were rhizomelic shortening of the long bones (100%, 17/17) and narrowing of the lumbar intervertebral space (88%, 15/17). Major complications included skeletal dysplasia (100%, 17/17), middle ear dysfunction (82%, 14/17), motor/language developmental delay (88%, 15/17), chronic pain (59%, 10/17), sleep apnea (53%, 9/17), obesity (41%, 7/17), foramen magnum stenosis (35%, 6/17), and hydrocephalus (24%, 4/17). All 17 children (100%) had FGFR3 mutations, among whom 13 had c.1138G>A hotspot mutations of the FGFR3 gene, 2 had c.1138G>C mutations of the FGFR3 gene, and 2 had unreported mutations, with c.1252C>T mutations of the FGFR3 gene in one child and c.445+2_445+5delTAGG mutations of the FGFR3 gene in the other child.

CONCLUSIONS

This study identifies the unreported mutation sites of the FGFR3 gene, which extends the gene mutation spectrum of ACH. ACH is a progressive disease requiring lifelong management through multidisciplinary collaboration.

Impact of achondroplasia on Latin American patients: a systematic review and meta-analysis of observational studies

Background

Achondroplasia (ACH), the most common form of disproportionate short stature, is caused by a pathogenic variant in the fibroblast growth factor receptor 3 gene. Recent advances in drug therapy for ACH have highlighted the importance of elucidating the natural history and socioeconomic burden of this condition. Recognition that there are many potential issues for the patient with ACH is the first step in planning cost-effective interventions in Latin America (LATAM), a vast geographic territory comprising countries with multicultural characteristics and wide socioeconomic differences. We conducted a systematic literature review to characterize the impact of ACH on affected individuals and on healthcare resources in LATAM countries.

Methods

Searches of the global medical literature as well as regional and local medical literature up to August 2020. Observational studies on patients with ACH from any LATAM country. Pairs of reviewers independently screened eligible articles, extracted data from included studies, and assessed their risk of bias.

Results

Fifty-three unique studies (28 case series and cross-sectional studies and 25 case reports) including data on 1604 patients were eligible. Of these studies, 11 had data available for meta-analysis. Both premature mortality and all-cause mortality in the pooled studies was 15% [95% Confidence Interval (CI) 1.0E−3 to 0.47; I² = 82.9%, p = 0.0029; three studies, n = 99 patients]. Frequency of cardio-respiratory-metabolic disorders was 17% [95% CI 0.04–0.37; I² = 90.3%, p < 0.0001; four studies, n = 230 patients]; nervous system disorders was 18% [95% CI 0.07–0.33; I² = 84.6%, p < 0.0001; six studies, n = 262 patients]; ear, nose, throat and speech disorders was 32% [95% CI 0.18–0.48; I² = 73.4%, p = 0.0046; five studies, n = 183 patients]; and spinal issues including stenosis, compression and associated pain was 24% [95% CI 0.07–0.47; I² = 91.3%, p < 0.0001; five studies, n = 235 patients].

Conclusions

There is currently evidence of high clinical burden in ACH patients in LATAM countries. Establishing the impact of ACH provides the necessary foundation for planning tailored and effective public health interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-02142-3.

Lifetime impact of achondroplasia: Current evidence and perspectives on the natural history

Achondroplasia, the most common form of disproportionate short stature, is caused by a variant in the fibroblast growth factor receptor 3 (FGFR3) gene. Advances in drug treatment for achondroplasia have underscored the need to better understand the natural history of this condition. This article provides a critical review and discussion of the natural history of achondroplasia based on current literature evidence and the perspectives of clinicians with extensive knowledge and practical experience in managing individuals with this diagnosis. This review draws evidence from recent and ongoing longitudinal natural history studies, supplemented with relevant cross-sectional studies where longitudinal research is lacking, to summarize the current knowledge on the nature, incidence, chronology, and interrelationships of achondroplasia-related comorbidities across the lifespan. When possible, data related to adults are presented separately from data specific to children and adolescents. Gaps in knowledge regarding clinical care are identified and areas for future research are recommended and discussed.

Pharmacotherapy in Rare Skeletal Diseases

New therapeutic approaches have been established in the field of rare skeletal diseases (e.g., for osteogenesis imperfecta, achondroplasia, hypophosphatemic rickets, hypophosphatasia, and fibrodysplasia ossificans progressiva). After elucidation of the underlying genotypes and pathophysiologic alterations of these diseases, new treatment options have been designed. Most drugs are based on an interaction with the disease-specific cascade of enzymes and proteins involved in the disease. Thereby an approved treatment is available for children with severe forms of hypophosphatasia and hypophosphatemic rickets (asfotase alfa, burosumab). Additionally, there are different phase 3 trials ongoing assessing the efficacy and safety of drugs for osteogenesis imperfecta, achondroplasia, and fibrodysplasia ossificans progressiva (denosumab, vosoritide, palovarotene).Because all these diseases are rare, the number of investigated patients in the trials is small, and the knowledge about rare side effects and long-term outcome is limited. Therefore it is recommended to treat the patients in specialized centers where the effects of the drugs can be evaluated and data about safety, side effects, and efficacy can be collected.Based on the fact that most drugs for rare diseases are highly expensive clear indications for start of a treatment, evaluation of the therapy and recommendations how long a treatment has to be administrated are urgently needed.

Epidemiology of achondroplasia: A population-based study in Europe

Achondroplasia is a rare genetic disorder resulting in short-limb skeletal dysplasia. We present the largest European population-based epidemiological study to date using data provided by the European Surveillance of Congenital Anomalies (EUROCAT) network. All cases of achondroplasia notified to 28 EUROCAT registries (1991-2015) were included in the study. Prevalence, birth outcomes, prenatal diagnosis, associated anomalies, and the impact of paternal and maternal age on de novo achondroplasia were presented. The study population consisted of 434 achondroplasia cases with a prevalence of 3.72 per 100,000 births (95%CIs: 3.14-4.39). There were 350 live births, 82 terminations of pregnancy after prenatal diagnosis, and two fetal deaths. The prenatal detection rate was significantly higher in recent years (71% in 2011-2015 vs. 36% in 1991-1995). Major associated congenital anomalies were present in 10% of cases. About 20% of cases were familial. After adjusting for maternal age, fathers >34 years had a significantly higher risk of having infants with de novo achondroplasia than younger fathers. Prevalence was stable over time, but regional differences were observed. All pregnancy outcomes were included in the prevalence estimate with 80.6% being live born. The study confirmed the increased risk for older fathers of having infants with de novo achondroplasia.

Current and Emerging Therapeutic Options for the Management of Rare Skeletal Diseases

Increasing knowledge in the field of rare diseases has led to new therapeutic approaches in the last decade. Treatment strategies have been developed after elucidation of the underlying genetic alterations and pathophysiology of certain diseases (e.g., in osteogenesis imperfecta, achondroplasia, hypophosphatemic rickets, hypophosphatasia and fibrodysplasia ossificans progressiva). Most of the drugs developed are specifically designed agents interacting with the disease-specific cascade of enzymes and proteins involved. While some are approved (asfotase alfa, burosumab), others are currently being investigated in phase III trials (denosumab, vosoritide, palovarotene). To offer a multi-disciplinary therapeutic approach, it is recommended that patients with rare skeletal disorders are treated and monitored in highly specialized centers. This guarantees the greatest safety for the individual patient and offers the possibility of collecting data to further improve treatment strategies for these rare conditions. Additionally, new therapeutic options could be achieved through increased awareness, not only in the field of pediatrics but also in prenatal and obstetric specialties. Presenting new therapeutic options might influence families in their decision of whether or not to terminate a pregnancy with a child with a skeletal disease.