BACKGROUND: Counseling osteogenesis imperfecta (OI) pregnancies is challenging due to the wide range of onsets and clinical severities, from perinatal lethality to milder forms detected later in life.
METHODS: Thirty-eight individuals from 36 families were diagnosed with OI through prenatal ultrasonography and/or postmortem clinical and radiographic findings. Genetic analysis was conducted on 26 genes associated with OI in these subjects that emerged over the past 20 years; while some genes were examined progressively, all 26 genes were examined in the group where no pathogenic variations were detected.
RESULTS: Prenatal and postnatal observations both consistently showed short limbs in 97%, followed by bowing of the long bones in 89%. Among 32 evaluated cases, all exhibited cranial hypomineralization. Fractures were found in 29 (76%) cases, with multiple bones involved in 18 of them. Genetic associations were disclosed in 27 families with 22 (81%) autosomal dominant and five (19%) autosomal recessive forms, revealing 25 variants in six genes (COL1A1, COL1A2, CREB3L1, P3H1, FKBP10, and IFITM5), including nine novels. Postmortem radiological examination showed variability in intrafamily expression of CREBL3- and P3H1-related OI.
CONCLUSIONS: Prenatal diagnosis for distinguishing OI and its subtypes relies on factors such as family history, timing, ultrasound, genetics, and postmortem evaluation.

Prolyl 3-hydroxylase 1 (P3H1) has been implicated in cancer development, but no pan-cancer analysis has been conducted on P3H1. In this study, for the first time, aspects associated with P3H1, such as the mRNA expression, any mutation, promoter methylation, and prognostic significance, the relationship between P3H1 and clinicopathological parameters, drug sensitivity, and immune cell infiltration were investigated by searching several databases including The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), cBioPortal, and The Tumor Immune Evaluation Resource (TIMER2.0) using bioinformatics tools. The findings indicate significant differential expression of P3H1 in most tumors when compared to normal tissues, with a strong association with clinical prognosis. A pan-cancer Cox regression analysis revealed that high P3H1 expression is significantly associated with low overall survival in patients with brain lower grade glioma, kidney clear cell carcinoma, adrenocortical cancer, liver hepatocellular carcinoma, mesothelioma, sarcoma, uveal melanoma, bladder urothelial carcinoma, kidney papillary cell carcinoma, kidney chromophobe, thymoma, and thyroid carcinoma. A negative correlation was observed between P3H1 DNA methylation and its expression. P3H1 is significantly associated with infiltrating cells, immune-related genes, tumor mutation burden, microsatellite instability, and mismatch repair. Finally, A significant correlation was found between P3H1 expression and sensitivity to nine drugs. Thus, enhanced P3H1 expression is associated with poor prognosis in a variety of tumors, which may be due to its role in tumor immune regulation and tumor microenvironment. This pan-cancer analysis provides insight into the function of P3H1 in tumorigenesis of different cancers and provides a theoretical basis for further in-depth studies to follow.

Osteogenesis imperfecta (OI) is a syndromic disorder of bone fragility with high variation in its clinical presentation. Equally variable is molecular aetiology; recessive forms are caused by approximately 20 different genes, many of which are directly implicated in collagen type I biosynthesis. Biallelic variants in prolyl 3-hydroxylase 1 (P3H1) are known to cause severe OI by affecting the competence of the prolyl 3-hydroxylation—cartilage associated protein—peptidyl-prolyl cis-trans isomerase B (P3H1-CRTAP-CyPB) complex, which acts on the Pro986 residue of collagen type I α 1 (COL1A1) and Pro707 collagen type I α 2 (COL1A2) chains. The investigation of an OI cohort of 146 patients in Vietnam identified 14 families with P3H1 variants. The c.1170+5G>C variant was found to be very prevalent (12/14) and accounted for 10.3% of the Vietnamese OI cohort. New P3H1 variants were also identified in this population. Interestingly, the c.1170+5G>C variants were found in families with the severe clinical Sillence types 2 and 3 but also the milder types 1 and 4. This is the first time that OI type 1 is reported in patients with P3H1 variants expanding the clinical spectrum. Patients with a homozygous c.1170+5G>C variant shared severe progressively deforming OI type 3: bowed long bones, deformities of ribcage, long phalanges and hands, bluish sclera, brachycephaly, and early intrauterine fractures. Although it remains unclear if the c.1170+5G>C variant constitutes a founder mutation in the Vietnamese population, its prevalence makes it valuable for the molecular diagnosis of OI in patients of the Kinh ethnicity. Our study provides insight into the clinical and genetic variation of P3H1-related OI in the Vietnamese population.

Osteogenesis imperfecta (OI) is a genetic disorder that causes skeletal fragility, multiple fractures and several extraskeletal disorders. Most cases of OI are caused by mutations in COL1A1/A2. Osteogenesis imperfecta type VIII typically causes a severe and fatal phenotype that presents at birth with severe osteopenia, congenital fractures and other clinical manifestations.
We describe the cases of an 11-year-old female and a 9-year-old male with homozygous truncating mutations in P3H1. Both cases were born with intrauterine fractures and suffered multiple fractures shortly after birth, requiring multiple operations to correct both fractures and severe scoliosis. The patients have been treated with pamidronate since the age of 2.
Whole exome sequencing (WES) was performed by Gene by Gene using Twist Bioscience technology. Initially, ~36.5 Mb of consensus coding sequences (targeting >98% of RefSeq and Gencode v. 28 regions obtained from the human genome) was replicated from fragmented genomic DNA using the Twist Human Core Exome Plus kit. The subsequent library was sequenced on the Illumina Novaseq Next Generation Sequencing platform to achieve at least ×20 reading depth for >98% of the targeted bases. Variant annotations and filtering was performed using Ingenuity Variant Analysis software.
We identified a homozygous mutation in the 3rd exon of P3H1 (c.628C>T/p.Arg210 Ter). Our cases broaden the phenotypic spectrum of OI type VIII as, to the best of our knowledge, these are the first postnatal cases with P3H1 (c.628C>T/p.Arg210 Ter) mutations published in the literature.
We present the first recorded postnatal cases from unrelated families of OI type VIII, broadening our understanding of the severe, but nonfatal spectrum of clinical phenotype of this recessive form of OI.

Background: Osteogenesis imperfecta (OI), is a heritable, heterogeneous connective tissue disorder, characterized by fragile bones. There are conflicting results about genotype-phenotype correlations and efficiency of bisphosphonate treatment in this disorder.Aim: We aimed to evaluate the clinical, genetic characteristics, and long-term follow-up results of children and adolescents with OI.Materials and methods: A two-center retrospective study was conducted using demographic, clinical, and genetic data obtained from the medical records of the patients.Results: Twenty-nine patients (62% male, median age; 3.6 years) with OI diagnosis from 26 families were included in the study. Thirteen different variants (nine were novel) were described in 16 patients in COL1A1, COL1A2, and P3H1 genes. Our siblings with homozygous P3H1 variants had a severe phenotype with intrauterine and neonatal fractures. Twenty-two patients were treated with bisphosphonates (17 of them with pamidronate, five with alendronate) with a median duration of 3.0 (1.6-4.8) years. Eleven patients (50%) suffered from fractures after the treatment. Haploinsufficiency variants in COL1A1 caused a milder skeletal phenotype with less fracture count and better treatment outcomes than structural variants. When compared with the anthropometric measurements at the initial diagnosis time, height Z-scores were lower on the last clinical follow-up (p = 0.009).Conclusions: We could not find an obvious genotype-phenotype correlation in Turkish OI patients with COL1A1 or COL1A2 variants. Treatment with pamidronate was effective in reducing fracture counts, without any long-term adverse effects.

Osteogenesis imperfecta (OI) type VIII (OMIM: 610915) is a rare autosomal recessive disorder characterized by white sclerae, severe growth deficiency, and bone fragility. This condition results from pathogenic variants of P3H1, a gene that codes for P3H1, an important protein involved in the prolyl-3-hydroxylation complex required for collagen type I folding. Here, we described a woman with OI type VIII due to a homozygous mutation of c.1914+1G>C (NM_001243246.1) in P3H1 and retinal detachment. We compared our case to five severe OI and retinal detachment cases reported in the literature. The only case previously reported with a molecular diagnosis had a similar mutation in P3H1 c.1914+1G>A and a giant retinal detachment. We suggest that individuals with OI type VIII should be submitted to careful fundoscopic examination.

Osteogenesis imperfecta (OI) is a highly clinically and genetically heterogeneous group of disorders. It is difficult to identify severe OI in the perinatal period. Here, a Chinese woman with a suspected history of fetal OI was referred to our institution at 19weeks of gestation, due to ultrasound inspection during antenatal screening, which revealed bulbous metaphyses, short humeri, and short thick bent femora in the fetus. Using targeted exome sequencing of 248 genes known to be involved in skeletal system diseases, we identified novel compound heterozygous mutation in the P3H1 gene in the fetus with OI type VIII: c.105_120del (p.D36Rfs*16) and c.2164C>T (p.Q722*). These two mutations were inherited from the father and mother, respectively. The mRNA level of P3H1 wasn\'t changed suggested that mRNA with this mutation escaped from nonsense-mediated RNA decay. Besides, the level of P3H1 was absence while the CRTAP was mildly decreased. In conclusion, our findings imply this novel compound heterozygous mutation as the molecular pathogenetic in a Chinese fetus with OI type VIII, and demonstrate that targeted next-generation sequencing (NGS) is an accurate, rapid, and cost-effective method in the genetic diagnosis of fetal skeletal dysplasia with genetic and clinical heterogeneity, especially for autosomal recessive skeletal disorders.