BACKGROUND: The protein kinase domain containing cytoplasmic (PKDCC) gene (OMIM#618821) is associated with bone development. Biallelic variants in the PKDCC gene can cause rhizomelic limb shortening with dysmorphic features.
METHODS: A fetus was found to be rhizomelic limb shortening at 16 weeks of gestation and amniocentesis was performed at 19 weeks of gestation. Genomic DNA extracted from the amniotic fluid was subjected to chromosomal microarray analysis (CMA), and Trio-total whole-exome sequencing (Trio-WES). Sanger sequencing was used to verify the candidate pathogenic variants. CMA was normal, while Trio-WES identified two compound heterozygous variants in the PKDCC gene, namely c.417_c.423delCGGCGCG insTCATGGGCTCAGTACAC(p.G140fs*35) and c.345G>A (p.W115*,379). Then the fetus was aborted and the development of its bone cells were compared with that of a normal fetus of similar gestational age by histopathological examination. Clinical findings of the fetus were shortening humerus and femur, synophrys, much hair on the side face, simian line on the right palm, etc. Histopathological examination showed that the affected fetus had increased proliferative chondrocytes, widened proliferative bands, and delayed bone mineralization.
CONCLUSIONS: We reported a prenatal case of rhizomelic shortening of limbs caused by compound heterozygous variants in the PKDCC gene, which emphasized the important role of Trio-WES for diagnosis of skeletal dysplasia in fetuses.

Stüve-Wiedemann syndrome (SWS) is a rare autosomal recessive disorder that is characterized by bowing of long bones, dysautonomia, temperature dysregulation, swallowing and feeding difficulties, and frequent respiratory infections. Respiratory distress and hyperthermic events are the leading causes of early neonatal death, and most patients are not expected to survive past infancy. Here, we report on the survival of a 5-year-old male with SWS, discussing his case presentation, providing a brief clinical course, and discussing the outcome. This case adds to the literature surrounding rare instances of childhood survivors of SWS and raises awareness for this syndrome to facilitate an earlier recognition, intervention, and genetic counseling for the families, thereby improving understanding of this disease and the health outcomes for the children affected by this condition.

Progressive pseudorheumatoid dysplasia (PPRD) is an autosomal recessive arthropathy, affecting school-aged children. It is characterized by progressive degeneration of the articular cartilage. The majority of the pathogenic variations are found in exon 2, exon 4, and exon 5 of the putative gene, CCN6 (WISP3). Three unrelated individuals with clinical diagnosis of PPD were included in this study. Detailed clinicoradiological evaluation was attempted with brief literature review. Exome sequencing was performed in all three cases. All the pathogenic variations detected in our cohort were located in exons 2 and 4 of WISP3 gene. Though the clinicoradiological features are already well described, this study in north India highlights the occurrence of a recurring pathogenic variant. The c.740_741del variant was a recurrent pathogenic variant seen in all three patients in this cohort. This may be a common pathogenic variant in the North Indian population; however, a larger cohort needs to be studied before drawing final conclusions. A proper molecular diagnosis is a must to end the diagnostic odyssey, safeguarding patients with PPRD from unnecessary use of drugs like corticosteroids.

There is an emerging body of evidence showing that young patients, post haematopoietic stem cell transplantation (HSCT), can develop skeletal changes that mimic an osteochondrodysplasia process. The key discriminator is that these children have had otherwise normal growth and skeletal development before the therapeutic intervention (HSCT), typically for a haematological malignancy. Herein we present that case of a boy who underwent HSCT for Haemophagocytic Lymphohistiocytosis (HLH) aged 2 years. Following Intervention with HSCT this boy\'s growth has severely decelerated (stature less than 1st centile matched for age) and he has developed a spondyloepiphyseal dysplasia.

BACKGROUND: Genome association studies have shown that gene-gene interactions or epistasis play a crucial role in identifying the etiology, prognosis, and treatment response of many complex diseases beyond their main effects. Skeletal dysplasias are a heterogeneous group of congenital bone and cartilage disorders with a genetic and gen-gen interaction etiology. The current classification of skeletal dysplasias distinguishes 461 diseases in 42 groups, and the incidence of all skeletal dysplasias is more than 1 in every 5000 newborns. The objective is to present the case of a patient with four variants that generates gen-gen interactions in the skeletal dysplasia.
METHODS: A 1-year-old male patient was diagnosed with skeletal dysplasia based on prenatal ultrasound showing micromelia and pyelocalyceal dilation. Postnatal physical examination revealed body disproportion and involvement of other organs and systems.
METHODS: A sequencing study and deletions/duplications analysis were performed for 358 candidate genes associated with skeletal dysplasia. The GeneMANIA interface was used to evaluate the expression network of genes associated with each other for the gen-gen interaction.
RESULTS: Four pathogenic variants were obtained two heterozygous variants with pathogenic significance in SLC26A, one heterozygous pathogenic variant in CLCN7 and another heterozygous pathogenic variant in CEP120. The GeneMANIA interface reveals 77.64% physical interactions, 8.01% co-expression, 5.37% prediction, 3.63% co-localization, 2.87% genetic interactions, 1.88% route of action, and 0.60% shared protein domains.
CONCLUSIONS: These results suggest that the interaction between these genes affects the activity of the inorganic anion exchanger, leading to disorganization of collagen fibers, early mineralization, and decreased assembly of fibronectin in the bone extracellular matrix. Identifying gene-gene interactions is a fundamental step in understanding proper cell function and thus understanding the pathophysiology of many complex human diseases, improving diagnosis, and the possibilities of new personalized therapies.

BACKGROUND: Anterior cervicothoracic myelomeningoceles are a rare pathology. In reported cases, treatment has included shunting, isolated resection and repair without deformity correction, or isolated deformity correction without meningocele repair. The authors describe a pediatric patient with an anterior cervicothoracic myelomeningocele presenting with progressive neurological decline, who underwent simultaneous treatment of the myelomeningocele to detether the spinal cord and achieve major correction of the scoliotic deformity.
METHODS: A 15-year-old girl was born with C7-T1-T2 hemivertebrae and anterior cervical myelomeningocele at C7-T1. She developed progressive cervical thoracic scoliosis, left hemiparesis initially, and additional right hemiparesis eventually. She underwent surgical repair via C7, T1, and T2 corpectomies with intradural detethering of the spinal cord. The scoliosis was treated with C7-T2 Ponte osteotomies and C2-T5 posterior fixation, followed by anterior reconstruction with a titanium cage and anterior plate from C6 to T3. The myelomeningocele was adequately treated with good correction of the patient\'s deformity. The patient had postoperative improvement in her strength and solid arthrodesis on postoperative imaging.
CONCLUSIONS: The authors describe the successful treatment of an anterior cervicothoracic myelomeningocele and associated scoliosis in a child. This is a unique report of a combined strategy to achieve both deformity correction and detethering of the spinal cord.

Skeletal dysplasia, also called osteochondrodysplasia, is a category of disorders affecting bone development and children\'s growth. Up to 552 genes, including fibroblast growth factor receptor 3 (FGFR3), have been implicated by pathogenic variations in its genesis. Frequently identified causal mutations in osteochondrodysplasia arise in the coding sequences of the FGFR3 gene: c.1138G>A and c.1138G>C in achondroplasia and c.1620C>A and c.1620C>G in hypochondroplasia. However, in some cases, the diagnostic investigations undertaken thus far have failed to identify the causal anomaly, which strengthens the relevance of the diagnostic strategies being further refined. We observed a Caucasian adult with clinical and radiographic features of achondroplasia, with no common pathogenic variant. Exome sequencing detected an FGFR3(NM_000142.4):c.1075+95C>G heterozygous intronic variation. In vitro studies showed that this variant results in the aberrant exonization of a 90-nucleotide 5\' segment of intron 8, resulting in the substitution of the alanine (Ala359) for a glycine (Gly) and the in-frame insertion of 30 amino acids. This change may alter FGFR3\'s function. Our report provides the first clinical description of an adult carrying this variant, which completes the phenotype description previously provided in children and confirms the recurrence, the autosomal-dominant pathogenicity, and the diagnostic relevance of this FGFR3 intronic variant. We support its inclusion in routinely used diagnostic tests for osteochondrodysplasia. This may increase the detection rate of causal variants and therefore could have a positive impact on patient management. Finally, FGFR3 alteration via non-coding sequence exonization should be considered a recurrent disease mechanism to be taken into account for new drug design and clinical trial strategies.

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

Spondylometaphyseal dysplasia Algerian type (MIM no.: 184253) is an uncommon autosomal dominant skeletal dysplasia caused by heterozygous mutations in the COL2A1 gene (MIM no.: 120140). In this case based review, we reported a 5-year-old boy with short stature, severe dorsolumbar scoliosis, lumbar hyperlordosis, short trunk, and severe genu valgum . Radiological examination showed platyspondyly, irregular metaphyseal radiolucencies intermingled with radiodensities, and corner fractures. The patient has a c.3275G > A; p.Gly1092Asp mutation in exon 47 of the COL2A1 gene and a variant of unknown significance in c.1366-13C > A in intron 21. This latter sequence variant could partially or completely disrupt the natural splice acceptor site of intron 21/exon 22 in the COL2A1 gene leading to a potential modification of the phenotypic severity.

Osteogenesis imperfecta (OI), also known as brittle bone disease, belongs to a rare heterogeneous group of inherited connective tissue disorders. In experienced prenatal centers, severe cases of OI can be suspected before birth from the first trimester prenatal ultrasound screening. In this article, we describe a case report of OI suspected at the 26th week of gestation and the patient\'s outcomes in infancy one year after birth, as well as compare our case to other prenatally or soon-after-birth suspected and/or diagnosed OI clinical case reports in the literature. This case was managed by a multidisciplinary team. In this clinical case, OI was first suspected when prenatal ultrasound revealed asymmetric intrauterine growth restriction and skeletal dysplasia features. The diagnosis was confirmed after birth using COL1A1 gene variant detection via exome sequencing; the COL1A1 gene variant causes OI types I-IV. The familial history was negative for both pregnancy-related risk factors and genetic diseases. At one year old, the patient\'s condition remains severe with bisphosphonate therapy.