Persistent elevations of alkaline phosphatase as an early indicator of GM1 gangliosidosis.

Abstract

GLB1-related disorders are autosomal recessive lysosomal diseases caused by enzymatic deficiency of β-galactosidase. Enzymatic deficiency of β-galactosidase may lead to one of two phenotypes, GM1 gangliosidosis or mucopolysaccharidosis IVB (MPS IVB). GM1 gangliosidosis is a neurodegenerative disorder with variable skeletal disease and involvement of other systems. The age of onset correlates with the extent of neurological involvement and established genotype/phenotype correlations. Mucopolysaccharidosis IVB is characterized by a skeletal dysplasia without neurological involvement. Diagnostic work-up for GLB1-related disorders includes enzyme analysis, biomarker analysis, molecular testing, and laboratory imaging studies. We report a patient who presented with persistent elevations of alkaline phosphatase (ALP) and subtle dysmorphic facial features. An initial skeletal survey at birth was unrevealing; however, a repeat at 3 months of age was abnormal with anterior beaking of the lumbar vertebrae and hemivertebrae of the lower cervical spine. Urinary glycosaminoglycan (GAG) analysis revealed a marked elevation of keratan sulfate (KS). Clinical exome sequencing revealed pathogenic heterozygous variants in GLB1, consistent with GLB1-related GM1 gangliosidosis. Our case demonstrates that persistent elevations of ALP may be an early indicator for GM1 gangliosidosis in an infant with progressive multisystem disease, indicating the need for early genetic consultation. This case also highlights the utility of repeat skeletal surveys with abnormalities detected at 3 months of age.

Department

Description

Provenance

Citation

Published Version (Please cite this version)

10.1016/j.ymgmr.2025.101191

Publication Info

Menkovic, Iskren, Monika Williams, Neelam Makhijani, Ruhan Wei, Sarah P Young, Areeg El-Gharbawy and Ashlee R Stiles (2025). Persistent elevations of alkaline phosphatase as an early indicator of GM1 gangliosidosis. Molecular genetics and metabolism reports, 42. p. 101191. 10.1016/j.ymgmr.2025.101191 Retrieved from https://hdl.handle.net/10161/32205.

This is constructed from limited available data and may be imprecise. To cite this article, please review & use the official citation provided by the journal.

Scholars@Duke

Wei

Ruhan Wei

Assistant Professor of Pathology
Young

Sarah Phyllis Young

Professor of Pediatrics

As a clinical biochemical geneticist and a director of the Duke Biochemical Genetics laboratory, my research interests are focused on improving laboratory diagnostics for rare inherited disorders of metabolism. I am actively involved in the development of assays using mass spectrometry and other analytical techniques. My current research on biomarkers for lysosomal storage disorders, such as Fabry and Pompe disease and the mucopolysaccharidoses includes monitoring the response to novel therapies in patients. I also have an interest in neurometabolic disorders such as the creatine deficiency syndromes and sulfite oxidase and molybdenum cofactors. These disorders can be diagnosed using liquid chromatography-tandem mass spectrometric assays that measure biomarkers in urine. Guanidinoacetate methyltransferase deficiency is a disorder that can be detected in the newborn period and is amenable to dietary therapy, and is thus a good candidate for newborn screening.

Stiles

Ashlee R. Stiles

Associate Professor of Pediatrics

Dr. Stiles is a fellow of the American College of Medical Genetics and Genomics trained in clinical biochemical genetics and molecular genetics. She is co-director of the Duke University Health System Biochemical Genetics Laboratory and external Referral Laboratory. In her work with the Biochemical Genetics laboratory, her research interests focus on improving and developing laboratory diagnostics for rare inborn errors of metabolism. In her role as director of the Referral laboratory, she works closely with hospital leadership on utilization management of genetic send-out tests. 


Unless otherwise indicated, scholarly articles published by Duke faculty members are made available here with a CC-BY-NC (Creative Commons Attribution Non-Commercial) license, as enabled by the Duke Open Access Policy. If you wish to use the materials in ways not already permitted under CC-BY-NC, please consult the copyright owner. Other materials are made available here through the author’s grant of a non-exclusive license to make their work openly accessible.