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Biomedical subjects

Roberto Mendoza-Londono

Publications and source records attributed to Roberto Mendoza-Londono.

8 recordsLinked to original sources
PubMed2026

A Phase 3 Trial of Vosoritide in Children with Hypochondroplasia.

BACKGROUND: Hypochondroplasia, a fibroblast growth factor receptor 3 (FGFR3)-related skeletal condition characterized by disproportionate short stature and a spectrum of clinical features, has no available targeted therapies. Vosoritide, a C-type natriuretic peptide analogue approved for the treatment of achondroplasia, is being investigated for hypochondroplasia. METHODS: In this phase 3, multicenter trial, children with hypochondroplasia who were 3 to less than 18 years of age were randomly assigned to receive once-daily subcutaneous injections of vosoritide or placebo for 52 weeks per weight-band dosing regimen. The primary end point was change from baseline in annualized growth velocity at week 52 versus placebo. Confirmatory statistical testing using hierarchical procedures to control for type I error at the one-sided 0.025 significance level (equivalent to the two-sided 0.05 level) was performed for the primary and six key secondary efficacy end points. The safety and side effect profile of vosoritide versus placebo was assessed. RESULTS: A total of 81 participants were randomly assigned to receive vosoritide (n=41) or placebo (n=40). At week 52, the least squares mean (LSM) change from baseline in annualized growth velocity was 1.95 cm/year with vosoritide versus -0.39 cm/year with placebo (LSM difference of 2.33 cm/year; 95% confidence interval, 1.85-2.82 cm/year; two-sided P<0.0001). Most participants in the vosoritide group (87.8%) and the placebo group (72.5%) experienced at least one adverse event (AE). There were no reports of grade 3 or higher AEs, AEs leading to treatment discontinuation, or deaths. CONCLUSIONS: One year of vosoritide treatment significantly increased linear growth in children with hypochondroplasia. (Funded by BioMarin Pharmaceutical; ClinicalTrials.gov number, NCT06455059.).

Journal Article↗
PubMed2025

A microcosting and cost consequence analysis from a randomized controlled trial comparing genome sequencing with exome sequencing for genetic diagnosis.

PURPOSE: Diagnosing rare diseases is costly. The objectives were to microcost exome (ES) and genome sequencing (GS) trios and estimate the incremental costs of GS per additional diagnosis from an institutional payer perspective. METHODS: Trios (proband plus biological parents) that are referred for sequencing were randomly assigned to ES or GS. Laboratory workflow and sequencing were microcosted. Total and category cost per trio were estimated probabilistically. Effectiveness was expressed as diagnostic yield (rates of diagnostic or partially diagnostic variants detected). Incremental costs and effectiveness were calculated. RESULTS: The mean total cost per trio was CAD 2888.79 (95% CI 2567.72, 3492.72) for ES (n = 329) and 4364.02 (95% CI 3984.94, 5013.67) for GS (n = 324). Reagents accounted for 34% and 61% of total costs for ES and GS, respectively. The incremental cost of GS was 1475.23. The diagnostic yield was 35.9% for ES and 32.7% for GS with a difference of 0.032 (95% CI: -0.041, 0.104, P value .397). CONCLUSION: GS demonstrated higher costs and a similar diagnostic yield to ES but was limited by technical capabilities at the time of the study. The study provides comprehensive costs for the economic evaluation comparing alternative diagnostic pathways and impetus for further evaluating variants uniquely detectable by GS.

Humans↗
PubMed2005

Characterization of a new syndrome that associates craniosynostosis, delayed fontanel closure, parietal foramina, imperforate anus, and skin eruption: CDAGS.

We describe the clinical characterization, molecular analyses, and genetic mapping of a distinct genetic condition characterized by craniosynostosis, delayed closure of the fontanel, cranial defects, clavicular hypoplasia, anal and genitourinary malformations, and skin eruption. We have identified seven patients with this phenotype in four families from different geographic regions and ethnic backgrounds. This is an autosomal recessive condition that brings together apparently opposing pathophysiologic and developmental processes, including accelerated suture closure and delayed ossification. Selected candidate genes--including RUNX2, CBFB, MSX2, ALX4, TWIST1, and RECQL4--were screened for mutations, by direct sequencing of their coding regions, and for microdeletions, by fluorescent in situ hybridization. No mutations or microdeletions were detected in any of the genes analyzed. A genomewide screen yielded the maximum estimated LOD score of +2.38 for markers D22S283 and D22S274 on chromosome 22q12-q13. We hypothesize that the gene defect in this condition causes novel context-dependent dysregulation of multiple signaling pathways, including RUNX2, during osteoblast differentiation and craniofacial morphogenesis.

Abnormalities, Multiple↗
PubMed2005

Acute lymphoblastic leukemia in a patient with Greig cephalopolysyndactyly and interstitial deletion of chromosome 7 del(7)(p11.2 p14) involving the GLI3 and ZNFN1A1 genes.

Greig cephalopolysyndactyly (GCPS; OMIM 175700) is an autosomal dominant condition caused by mutations of the gene GLI3, located on 7p13. To date, several cases of deletions and/or translocations involving this locus have been reported in patients with GCPS. GLI3 is a transcription factor from the GLI-Kruppel gene family that has been implicated in three distinct entities: GCPS, Pallister-Hall syndrome, and postaxial polydactyly type A. The zinc finger protein, subfamily 1, member 1 gene (ZNFN1A1; OMIM 603023), on 7p12, codes for a lymphoid-restricted zinc finger transcription factor, ZNFN1A1, also called IKAROS, that regulates lymphocyte differentiation and has been associated with the development of childhood leukemia. We present the case of a 9-year-old Latin-American boy who was referred for stem cell transplantation because of recurrent acute lymphoblastic leukemia (ALL). On evaluation, he was found to have dysmorphic features consistent with GCPS, including a prominent forehead, down-slanting palpebral fissures, 1-2-3 toe syndactyly, broad thumbs and first toes, and mild developmental delay. He had developed ALL at 5 years of age. Chromosome analysis of bone marrow and fibroblastic cells showed an interstitial deletion of chromosome arm 7p, del(7)(p11.2p14), in 74% and 44% of the cells, respectively. We performed FISH analysis with a BAC clone containing the ZNFN1A1 gene and demonstrated that it is contained in the deleted segment. To our knowledge, this is the first report of a patient with GCPS and leukemia. We hypothesize that constitutional deletion of the ZNFN1A1 gene in this patient may have resulted in an increased risk of lymphoid malignancy.

Bone Marrow Cells↗
PubMed2004

Attenuated phenotype in a child with trisomy for 1q due to unbalanced X;1 translocation [46,X,der(X),t(X;1)(q28;q32.1)].

We report a case of an X;1 translocation in a 9-month-old female infant with mild dysmorphic features and developmental delay. High-resolution chromosome analysis revealed a de novo, unbalanced translocation between chromosomes X and 1 [46,X,der(X),t(X;1)(q28;q32.1)]. Breakpoints on the derivative X and the size of the translocated segment have been defined by fluorescence in situ hybridization (FISH) with Xq and 1q specific probes. The rearrangement in this patient results in monosomy for Xq28-qter and trisomy for 1q32.1-qter. Replication studies demonstrated late replication of the derivative X in 80% of the observed cells, with the exception of 20% of the cells where X inactivation failed to spread into the translocated 1q segment. Patients with pure trisomy for the distal segment of 1q present a considerably more severe phenotype compared to that seen in our patient, including facial dysmorphisms, urogenital and cardiac anomalies. We suggest that the absence of many of the characteristic features for trisomy 1q in our patient, may reflect a mosaic pattern of inactivation of the translocated autosomal segment on the derivative X chromosome.

Abnormalities, Multiple↗
PubMed2004

von Voss-Cherstvoy syndrome with transient thrombocytopenia and normal psychomotor development.

We report a 16-month-old patient with meningoencephalocele, absence of the radii, ambiguous genitalia, and transient neonatal thrombocytopenia. The phenotype strongly suggests the von Voss-Cherstvoy syndrome. Thrombocytopenia was present during the first 2 weeks of life and not found in subsequent determinations. This observation suggests that thrombocytopenia is a transient part of the syndrome. Among the patients reported so far our case appears to represent the mildest phenotype. Despite the neonatal complications and meningoencephalocele, the patient currently has normal psychomotor development.

Abnormalities, Multiple↗
PubMedDate not supplied

Mutations and promoter SNPs in RUNX2, a transcriptional regulator of bone formation.

Cleidocranial dysplasia (CCD) is a dominantly inherited skeletal malformation syndrome with high penetrance and variable expressivity. It is caused by loss of function mutations in the RUNX2 gene that encodes for a transcription factor essential for osteoblast differentiation and chondrocyte maturation. To identify new pathogenic mutations associated with CCD we screened 38 CCD patients for mutations in the RUNX2 coding sequence. We also report the mutation screening of the "bone-related" RUNX2 promoter in CCD patients without mutation in the RUNX2 coding region. We identify eight new and three previously described mutations in the RUNX2 gene. Additionally, a total of five sequence variants in the RUNX2 promoter were detected. Three of them occur within putative zinc finger transcription factor binding sites. DHPLC analysis of chromosomes from the control population and CCD patients showed that two promoter sequence variants were unique for CCD families. Electrophoretic mobility shift assay (EMSA) with protein extracts from ROS17/2.8 and C3H10T1/2 cell lines demonstrated that the promoter sequence variants altered DNA-protein binding specificity. Moreover, one of the variants significantly decreased the expression of a RUNX2 reporter gene in osteoblastic ROS17/2.8 cells, but not in multipotent, mesenchymal C3H10T1/2 cells. Interestingly, one of these sites bound the TRPS1 transcription factor and we demonstrated that TRPS1 is able to repress the RUNX2 promoter. The in vitro functional studies in conjunction with analysis of clinical phenotype of CCD patients suggest that these promoter sequence variants may affect transcriptional activity of the RUNX2 gene. Analysis of the promoter variants and RUNX2-interacting proteins may help to identify important cis-elements and trans-factors that regulate the RUNX2 transcriptional network and identify new susceptibility markers for more common bone disorders.

Animals↗