Achondroplasia

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.

Novel Physique Index for the Screening of Skeletal Dysplasia at Birth

This study aimed to devise a novel physique index and investigate its accuracy in identifying newborns with skeletal dysplasia in comparison with head circumference (HC)/height (HT) ratio. The birth weight (W), HT, and HC at birth of 1500 newborns were retrospectively collected. The linear regression equations and coefficients of determination (R²) were determined. The formulated equation was corrected by the mean weight for gestational age at birth (Wcorr) as a novel physique index for screening skeletal dysplasia. The index accuracy was assessed using receiver operating characteristic (ROC) curves in 11 newborns by fetal ultrasound and compared with that of the HC/HT ratio. The R² values between W and HT, (HT)², and (HT) ³ were 0.978, 0.990, and 0.993, respectively. Those between W and HC, (HC)², and (HC)³ were 0.974, 0.984, and 0.988, respectively. W/Wcorr × (HC/HT)³ was used as a novel physique index. Seven newborns had skeletal dysplasia. Our novel physique index had a higher area under the curve (AUC), sensitivity, and specificity than the HC/HT ratio (AUC: 1.00 vs. 0.86, sensitivity: 1.00 vs. 0.86, and specificity: 1.00 vs. 0.75, respectively). Our novel physique index was more accurate than HC/HT ratio and has the potential to accurately identify newborns with skeletal dysplasia.

Frequency of skeletal anomalies in fetal and neonatal autopsies

Introduction: Skeletal anomalies are a heterogeneous group of disorders including changes in bone shape, size, and density that cause abnormalities of the extremities, trunk, and head. They rank second in Europe in the frequency of all congenital anomalies. The most common skeletal anomalies include head, face and limb anomalies. Aim: The aim of this study was to determine the frequency of skeletal anomalies and their association with anomalies of internal organs, as well as to show the age of the mother and the gestational week of the fetus with established skeletal anomalies. Material and methods: All fetal and neonatal autopsies in the period from January 1, 2018 to December 31, 2020 at the Institute of Pathology "Djordje Joannovic" of the Faculty of Medicine University of Belgrade were analyzed. In the mentioned period, 580 fetal and neonatal autopsies were performed. Clinical data were obtained from the Gynecology and Obstetrics Clinic "Narodni Front" on the basis of completed requests for clinical autopsy. Descriptive statistics methods were used (data are presented as absolute numbers and percentage frequencies). Results: The most common skeletal anomalies are divided into seven groups: spina bifida (20; 33.34%), limb anomalies (16; 26.67%), head and face bone anomalies (15; 25%), joint anomalies (2; 3.33%), achondroplasia (3; 5%), osteogenesis imperfecta (2; 3.33%) and other anomalies (2; 3.33%). The most common associated anomalies were central nervous system (CNS) abnormalities, followed by heart and kidney abnormalities. The youngest mother was 15 years old, and the oldest was 47 years old. The mean age of the mothers was 30 years. Conclusion: In our study, the most common anomaly was spina bifida, while limb anomalies and craniofacial anomalies are next in frequency. Skeletal anomalies were often associated with anomalies of the heart, kidneys, and CNS. They were mostly diagnosed between the 22nd and 27th gestational week. Our results showed that skeletal anomalies are more common in fetuses or neonates of mothers older than 30 years.