Findings published in The American Journal of Pathology pave the way for uncovering molecular targets and development of treatment options for this rare disease

May 18, 2026 – Researchers have developed a novel mouse model that replicates severe geleophysic dysplasia, including short stature, heart valve alterations, and early lethality—characteristics of this rare disease. The findings from the study in The American Journal of Pathology, published by Elsevier, provide a basis for the identification of molecular mechanisms underlying geleophysic dysplasia, which can then be targeted for therapeutic purposes.

Geleophysic dysplasia is a debilitating disease with no treatment options, despite an increased risk of childhood mortality and significant morbidity. It is caused by recessive mutations in ADAMTSL2, a gene responsible for regulating tissue and cell function, or dominant mutations in FBN1 or LTBP3. Patients with geleophysic dysplasia develop severe short stature and other skeletal abnormalities, characteristic facial features, thick skin, and hypermuscular build. Life-threatening complications can arise from progressive heart valve disease and narrowing of the large airways, resulting in ~30% mortality before the age of 5 years.

Due to the paucity of preclinical models that reflect the clinical variability of geleophysic dysplasia, the researchers of this study set out to introduce a patient-derived genetic ADAMTSL2 variant, which results in a D167N change on the amino acid level into the mouse genome to better understand the underlying mechanisms of geleophysic dysplasia and facilitate testing of therapeutic approaches.

“We successfully generated a novel, preclinical model of severe geleophysic dysplasia that phenocopies the human disease,” explains co-lead investigator Dirk Hubmacher, PhD, Orthopedic Research Laboratories, Leni & Peter W. May Department of Orthopedics, and Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai. “Mutant D167N mice were smaller with shorter bones and developed cardiovascular anomalies that include enlarged heart valves. We also identified changes in the growth plate, potentially underlying the compromised bone growth.”

First author and co-investigator Connie Lin, Department of Pediatrics, Case Western Reserve University School of Medicine, notes, "Beyond the skeletal abnormalities, the mice also developed airway obstruction and structural changes in the aortic valves—two complications that are particularly dangerous for patients with geleophysic dysplasia. Seeing these same features appear in the model was exciting because it highlights how broadly this mutation affects connective tissue and provides a powerful way to study how these life-threatening complications develop.”

Although the results of the study are in line with the expectations based on previously published insights, the researchers were somewhat surprised that only one of the heart valves, the aortic valve, appeared to be affected in the D167N mice. This is different in patients, where the involvement of all heart valves has been described in case reports.

“Since ADAMTSL2 regulates different signaling pathways in different cell types, a one-size-fits all approach may not be successful, and in particular, the mechanisms underlying the heart valve and airway changes need to be identified,” points out co-lead investigator Timothy J. Mead, PhD, Department of Pediatrics, Case Western Reserve University School of Medicine, and Division of Pediatric Cardiology, University Hospitals Rainbow Babies & Children's Hospital. “Understanding the extracellular matrix composition that affects this disease is essential for generating novel, preclinical models and uncovering molecular targets to identify treatment options."

Co-investigator Ana D. Alcocer, Department of Pediatrics, Case Western Reserve University School of Medicine, concludes, "Having a model like this is critical because it allows us to better understand the progression of this life-threatening disease and provides a basis for the investigation of potential therapeutic targets that could impact patients’ lives.”