Biomedical subjects

Julian A Martinez-Agosto

Publications and source records attributed to Julian A Martinez-Agosto.

4 recordsLinked to original sources

PubMed2025

Precision diagnostic and therapeutic interventions in rare genetic neurodevelopmental disorders.

Neurodevelopmental disorders (NDDs) include a broad spectrum of phenotypes spanning from intellectual disability (ID) to developmental delay (DD) and autism spectrum disorder (ASD). As neurodevelopmental phenotypes are a common presenting feature of an underlying genetic condition, professional medical organizations recommend genetic testing for all individuals with a NDD. When testing is pursued, identified genetic differences can lead to personalized clinical management with early diagnosis supporting the development of surveillance and intervention for co-occurring adverse health outcomes. Despite this, barriers to testing have prevented individuals from receiving a genetics referral and testing. Current therapeutic modalities including small molecule drugs, gene therapies, and antisense oligonucleotide therapies have emerged and shown promise in preclinical trials with therapeutic drugs gaining FDA approval. However, translational challenges are extensive, especially for identifying biomarkers of drug effects in the CNS. In this review, we discuss diagnostic approaches and clinical utility of genetic testing for rare genetic neurodevelopmental disorders, emerging development of individualized therapies, and progress for current therapeutics in addition to challenges with clinical translation and delivery. We will highlight opportunities for early diagnosis and treatment that are steadily gaining ground in favor of optimizing long-term health outcomes and improving quality of life for neurodiverse individuals. IMPACT: The path from genomics to therapeutics for neurodevelopmental disorders continues to present multiple opportunities and challenges. While emerging genome-wide sequencing and gene editing technologies deliver increased diagnostic yields and alternatives to life-long small molecule therapies, clinical translation has been challenging due to inherent cost and genetic heterogeneity. Limited access to genetic testing despite practice guidelines remains a barrier towards precision therapeutics for rare neurodevelopmental disorders, while pre-clinical investigations face obstacles when translating to human subjects. This review will summarize the impact of existing successes in diagnosis and therapeutics for neurodevelopmental disorders while highlighting ongoing challenges and areas of future opportunities.

Humans↗

PubMed2025

Joint, multifaceted genomic analysis enables diagnosis of diverse, ultra-rare monogenic presentations.

Genomics for rare disease diagnosis has advanced at a rapid pace due to our ability to perform in-depth analyses on individual patients with ultra-rare diseases. The increasing sizes of ultra-rare disease cohorts internationally newly enables cohort-wide analyses for new discoveries, but well-calibrated statistical genetics approaches for jointly analyzing these patients are still under development. The Undiagnosed Diseases Network (UDN) brings multiple clinical, research and experimental centers under the same umbrella across the United States to facilitate and scale case-based diagnostic analyses. Here, we present the first joint analysis of whole genome sequencing data of UDN patients across the network. We introduce new, well-calibrated statistical methods for prioritizing disease genes with de novo recurrence and compound heterozygosity. We also detect pathways enriched with candidate and known diagnostic genes. Our computational analysis, coupled with a systematic clinical review, recapitulated known diagnoses and revealed new disease associations. We further release a software package, RaMeDiES, enabling automated cross-analysis of deidentified sequenced cohorts for new diagnostic and research discoveries. Gene-level findings and variant-level information across the cohort are available in a public-facing browser ( https://dbmi-bgm.github.io/udn-browser/ ). These results show that case-level diagnostic efforts should be supplemented by a joint genomic analysis across cohorts.

Humans↗

PubMed2024

Genomics-informed neuropsychiatric care for neurodevelopmental disorders: Results from a multidisciplinary clinic.

PURPOSE: Patients with neurodevelopmental disorders (NDDs) have high rates of neuropsychiatric comorbidities. Genomic medicine may help guide care because pathogenic variants are identified in up to 50% of patients with NDDs. We evaluate the impact of a genomics-informed, multidisciplinary, neuropsychiatric specialty clinic on the diagnosis and management of patients with NDDs. METHODS: We performed a retrospective study of 316 patients from the University of California, Los Angeles Care and Research in Neurogenetics Clinic, a genomics-informed multidisciplinary clinic. RESULTS: Among the 246 patients who underwent genetic testing, 41.8% had a pathogenic or likely pathogenic variant. Patients had 62 different genetic diagnoses, with 12 diagnoses shared by 2 or more patients, whereas 50 diagnoses were found in only single patients. Genetic diagnosis resulted in direct changes to clinical management in all patients with a pathogenic or likely pathogenic variant, including cascade testing (30.6%), family counseling (22.2%), medication changes (13.9%), clinical trial referral (2.8%), medical surveillance (30.6%), and specialty referrals (69.4%). CONCLUSIONS: A genomics-informed model can provide significant clinical benefits to patients with NDDs, directly affecting management across multiple domains for most diagnosed patients. As precision treatments advance, establishing a genetic diagnosis will be critical for proper management. With the growing number of rare neurogenetic disorders, clinician training should emphasize core principles of genomic medicine over individual syndromes.

Humans↗

PubMed2024

Loss-of-function in RBBP5 results in a syndromic neurodevelopmental disorder associated with microcephaly.

PURPOSE: Epigenetic dysregulation has been associated with many inherited disorders. RBBP5 (HGNC:9888) encodes a core member of the protein complex that methylates histone 3 lysine-4 and has not been implicated in human disease. METHODS: We identify 5 unrelated individuals with de novo heterozygous variants in RBBP5. Three nonsense/frameshift and 2 missense variants were identified in probands with neurodevelopmental symptoms, including global developmental delay, intellectual disability, microcephaly, and short stature. Here, we investigate the pathogenicity of the variants through protein structural analysis and transgenic Drosophila models. RESULTS: Both missense p.(T232I) and p.(E296D) variants affect evolutionarily conserved amino acids located at the interface between RBBP5 and the nucleosome. In Drosophila, overexpression analysis identifies partial loss-of-function mechanisms when the variants are expressed using the fly Rbbp5 or human RBBP5 cDNA. Loss of Rbbp5 leads to a reduction in brain size. The human reference or variant transgenes fail to rescue this loss and expression of either missense variant in an Rbbp5 null background results in a less severe microcephaly phenotype than the human reference, indicating both missense variants are partial loss-of-function alleles. CONCLUSION: Haploinsufficiency of RBBP5 observed through de novo null and hypomorphic loss-of-function variants is associated with a syndromic neurodevelopmental disorder.

Humans↗