Hypophosphatasia (HPP) is a congenital skeletal dysplasia. Enzyme replacement therapy (ERT) improves survival and bone mineralization of patients with perinatal severe HPP. However, there are few reports of ERT in patients with perinatal benign HPP, and its long-term efficacy remains unclear. Herein, we report the case of a boy with perinatal benign HPP who was initiated on early ERT with asfotase alpha. The patient was suspected of having HPP because of shortened limbs and deformed long bones on fetal 3D-CT. He was diagnosed with HPP based on clinical manifestations, low serum alkaline phosphatase levels, and ALPL gene variants. At the age of two years and three months, he had muscle weakness and motor developmental delay requiring support to walk, and ERT was initiated. His muscle strength improved immediately, and he could walk independently two months after starting ERT. Shortening and bowed limbs improved, and his body height increased from -3.48 SD (at the age of two years and three months) to -1.71 SD (at the age of nine years and eight months) after starting ERT. Hence, early ERT effectively improves motor development, bone deformity, and short stature in patients with perinatal benign HPP.

The current case report presents the postmortem examination findings of a 17-week-old female fetus displaying thanatophoric dysplasia type 1 (TD-1) due to a known fibroblast growth factor receptor 3 (FGFR3) gene mutation. Gross and X-ray examination revealed significant abnormalities, including skeletal malformations with prominent TD-1 femur curvature. Microscopical evaluation indicated inadequate histological growth for the gestational age, with specific organ immaturity noted in multiple hematoxylin and eosin sections from internal organs, bone from epiphyses and diaphyses levels. Immunohistochemical analysis was conducted using specific markers, such as S100, CD34, CD117, glycophorin-C, and myeloperoxidase, to identify various hematopoietic and mesenchymal cell types. Furthermore, this report underscores the often-overlooked aspect of fetal hematopoiesis in cases diagnosed with TD-1, shedding light on the development of hematopoietic cells and their markers in various tissues, with a particular emphasis on the investigation of bone marrow foci in areas with incipient or no apparent ossification. Immunohistochemical identification of hematopoiesis also served as an indirect way to identify areas of incipient or abnormal ossification.

Hereditary connective tissue disorders (HCTDs) are a heterogeneous group of inherited diseases. These disorders show genetic mutations with loss of function of primary components of connective tissue, such as collagen and elastic fibers. There are more than 200 conditions that involve hereditary connective tissue disorders, while the most known are Marfan syndrome, Osteogenesis Imperfecta, and Ehlers-Danlos syndromes. These disorders need continuous updates, multidisciplinary skills, and specific methodologic evaluations sharing many medicolegal issues. Marfan syndrome and Ehlers-Danlos syndromes show a high risk of early sudden death. As a consequence of this, postmortem genetic testing can identify novel genotype-phenotype correlations which help the clinicians to assess personalized cardiovascular screening programs among the ill subjects. Genetic testing is also essential to identify children suffering from Osteogenesis Imperfecta, especially when a physical abuse is clinically suspected. However, this is a well-known clinical problem even though there are still challenges to interpret genetic data and variants of unknown significance due to the current extensive use of new genetic/genomic techniques. Additionally, the more significant applications and complexities of genomic testing raise novel responsibilities on the clinicians, geneticists, and forensic practitioners as well, increasing potential liability and medical malpractice claims. This systematic review provides a detailed overview on how multidisciplinary skills belonging to clinicians, medicolegal consultants, radiologists, and geneticists can cooperate to manage HCTDs from autopsy or clinical findings to genetic testing. Thus, technical aspects need to be addressed to the medicolegal community since there is no consensus works or guidelines which specifically discuss these issues.

Acromesomelic dysplasia (AMD) is an umbrella term given to a heterogeneous group of progressive skeletal disorders characterized by short limbed dwarfism associated with disproportionate shortening of middle and distal segments of the upper as well as lower limbs. Although specific skeletal anomalies are difficult to diagnose antenatally, but because of their antenatal and postnatal implications and a possibility of reoccurrence in following pregnancies, such skeletal anomalies need to be actively addressed. A combination of radiologic, pathologic, genetic and molecular investigation prenatally as well as postnatally is required to classify a specific congenital skeletal dysplasia. Once the genetic make-up of fetal skeletal dysplasia is deciphered, a meaningful genetic counselling could be offered for future pregnancies of affected families. We describe a case of primigravida diagnosed with fetal unilateral upper limb AMD on antenatal ultrasound done at early second trimester. The radius and ulna of left upper limb were abnormally short (less than 5th centile of the mean for that gestational age). The left hand was also hypoplastic. Rest of the sonographic anomaly scan was normal. To the best of our knowledge, AMD limited to unilateral upper limb diagnosed antenatally as an isolated finding is not described in the medical literature so far.

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

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.

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.

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

Ultrasonography (US) is the first-line diagnostic tool used to assess fetal musculoskeletal (MSK) anomalies. Associated anomalies in other organ systems may benefit from evaluation via Magnetic Resonance Imaging (MRI). In this study, we compared the diagnostic accuracy of US and MRI to diagnose fetal MSK (primary objective) and non-MSK anomalies (secondary objective). We describe additional findings by low-dose computerized tomography (CT) in two cases incompletely characterized via US and MRI.

This was an IRB-approved retrospective study of consecutive patients with suspected fetal MSK anomalies examined between December 2015 and June 2020. We compared individual MSK and non-MSK anomalies identified via US, MRI, and CT with postnatal outcomes. Sensitivity and specificity for US and MRI were calculated and compared.

A total of 31 patients with 112 MSK and 43 non-MSK anomalies were included. The sensitivity of MRI and US for MSK anomalies was not significantly different (76.6% vs. 61.3%, p = 0.3). Low-dose CT identified eight additional skeletal anomalies. MRI diagnosed a higher number of non-MSK anomalies compared to US (81.4% vs. 37.2%, p < 0.05).

Fetal MRI and US have comparable sensitivity for MSK anomalies. In selected cases, low-dose CT may provide additional information. Fetal MRI detected a larger number of non-MSK anomalies in other organ systems compared to US. Multimodality imaging combining all the information provided by MRI, US, and CT, if necessary, ultimately achieved a sensitivity of 89.2% (95% CI: 83.4% to 95.0%) for the diagnosis of musculoskeletal anomalies and 81.4% for additional anomalies in other organs and systems.

Skeletal anomalies are rare, requiring a systematic ultrasound (US) examination of each skeletal part when there is suspicion of a skeletal dysplasia. Although US examination can provide good evaluation of the fetal bones and cartilage, ultra-low-dose three-dimensional (3-D) multi-detector computed tomography (CT) is a useful complementary tool that can significantly improve prenatal diagnostic accuracy in select cases. Given that ultra-low-dose fetal CT remains an irradiating technique, indications should result from a multidisciplinary consensus, acquisition protocols should be optimized and the reporting standardized. In this paper we discuss guidelines from the Fetal Imaging Task Force of the European Society of Paediatric Radiology for indications, protocols and reporting of ultra-low-dose fetal CT.

Fetal skeletal dysplasias involving limbs and hands are rare congenital malformations. Prenatal two-dimensional ultrasound diagnosis of fetal limb defects has a sensitivity of about 30%; however, an increased detection rate may be obtained using three-dimensional (3-D) ultrasound in the rendering mode. 3-D ultrasound may be used as a complementary method providing additional information. Currently, magnetic resonance imaging (MRI), with the emergence of ultrafast imaging techniques and new sequences, allows for better diagnosis of several fetal skeletal dysplasias such as limb reduction defects and neuromuscular disorders. 3-D volumetric images from ultrasound or MRI scan data allow 3-D ultrasound reconstructions of virtual/physical models, and virtual reality can help researchers to improve our understanding of both normal and abnormal fetal limb/hand anatomy. In this article, we review the embryological development of fetal hands and their main anomalies including prenatal diagnostic methods, genetic counseling, the role of orthopedic and plastic surgery reconstruction, and new perspectives in fetal surgery.

To examine the feasibility of using crown-chin length (CCL) to crown-rump length (CRL) ratio in screening for skeletal dysplasia in the first trimester.

Four hundred and eighteen singleton pregnant women were recruited and the ratio of CCL to CRL was calculated according to gestational age. Fetuses with skeletal dysplasia were collected from database in the last 10 years. The CCL/CRL ratios were then calculated and the unpaired Student's t-test was to determine the significance of differences between normal fetuses and fetuses with skeletal dysplasia. Receiver operating characteristic curve was used to show the clinical sensitivity and specificity.

In 418 normal fetuses, CCL increased linearly with gestation from a mean of 20 mm at 11⁺⁰ weeks to 37 mm at 13⁺⁶ weeks (CCL [mm] = 0.51-4 CRL, R²  = 0.824, P = .000). There was also a significant linear association between fetal CCL/CRL ratio and CRL, from a mean of 0.48 at 11⁺⁰ weeks to 0.41 at 13⁺⁶ weeks (CCL/CRL = 0.63-3 CRL, R²  = 0.108, P = .000). In 154 skeletal dysplasia cases, early pregnancy ultrasound images were available in only 16 cases. The CCL/CRL ratio in 10 of 16 fetuses with skeletal dysplasia was above the 95th percentile. Using the 95th percentile as a cut-off, the detection rate, specificity, false-positive rate, and positive likelihood ratio are 62.5, 72.6, 5, and 17.5%, respectively.

Increased fetal CCL/CRL ratio at 11-14 weeks' gestation is associated with an increased risk of skeletal dysplasia and may be useful in first-trimester screening for this condition.

Osteogenesis imperfecta (OI), or brittle bone disease, is a heterogeneous disorder characterised by bone fragility, multiple fractures, bone deformity, and short stature. OI is a heterogeneous disorder primarily caused by mutations in the genes involved in the production of type 1 collagen. Severe OI is perinatally lethal, while mild OI can sometimes not be recognised until adulthood. Severe or lethal OI can usually be diagnosed using antenatal ultrasound and confirmed by various imaging modalities and genetic testing. The combination of imaging parameters obtained by ultrasound, computed tomography (CT), and magnetic resource imaging (MRI) can not only detect OI accurately but also predict lethality before birth. Moreover, genetic testing, either noninvasive or invasive, can further confirm the diagnosis prenatally. Early and precise diagnoses provide parents with more time to decide on reproductive options. The currently available postnatal treatments for OI are not curative, and individuals with severe OI suffer multiple fractures and bone deformities throughout their lives. In utero mesenchymal stem cell transplantation has been drawing attention as a promising therapy for severe OI, and a clinical trial to assess the safety and efficacy of cell therapy is currently ongoing. In the future, early diagnosis followed by in utero stem cell transplantation should be adopted as a new therapeutic option for severe OI.