- Glycine encephalopathy, also known as autosomal recessive nonketotic hyperglycinemia is caused by mutations in the genes encoding components of the glycine cleavage system. It is caused by mutations in the glycine transporter 1 (GLYT1). Glycine encephalopathy an acute metabolic emergency result of an inborn error of metabolism which can result in significant morbidity, progressive neurologic injury, or death. Optimal outcomes of this complication depend upon recognition of the signs and symptoms of metabolic disease, prompt evaluation and referral to a center for evaluation and management. Mutations involved in the glycine cleavage system are inherited in an autosomal recessive pattern.
- The Igenomix Glycine Encephalopathy Precision Panel can be used to make an accurate and directed diagnosis ultimately leading to a better management and prognosis of the disease. It provides a comprehensive analysis of the genes involved in this disease using next-generation sequencing (NGS) to fully understand the spectrum of relevant genes involved.
- The Igenomix Glycine Encephalopathy Precision Panel is indicated for those patients with a clinical suspicion or diagnosis with or without the following manifestations during the newborn period:
- Respiratory failure requiring mechanical ventilation
- Severe hypotonia progressing to limb hypertonicity
- Startle-like responses
- Dysmorphic features
- Musculoskeletal abnormalities
The clinical utility of this panel is:
- The genetic and molecular confirmation for an accurate clinical diagnosis of a symptomatic patient.
- Early initiation of multidisciplinary treatment including paediatricians, neurologists, geneticists, genetic counsellors, dietitians, physiotherapists, occupational therapies and orthopaedic surgeons. Dietary restrictions can help prevent acute flares.
- Risk assessment and genetic counselling of asymptomatic family members according to the mode of inheritance.
- Improvement of delineation of genotype-phenotype correlation
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Kurolap, A., Armbruster, A., Hershkovitz, T., Hauf, K., Mory, A., Paperna, T., Hannappel, E., Tal, G., Nijem, Y., Sella, E., Mahajnah, M., Ilivitzki, A., Hershkovitz, D., Ekhilevitch, N., Mandel, H., Eulenburg, V., & Baris, H. N. (2016). Loss of Glycine Transporter 1 Causes a Subtype of Glycine Encephalopathy with Arthrogryposis and Mildly Elevated Cerebrospinal Fluid Glycine. American journal of human genetics, 99(5), 1172–1180. https://doi.org/10.1016/j.ajhg.2016.09.004
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Poothrikovil, R. P., Al Thihli, K., Al Futaisi, A., & Al Murshidi, F. (2019). Nonketotic Hyperglycinemia: Two Case Reports and Review. The Neurodiagnostic journal, 59(3), 142–151. https://doi.org/10.1080/21646821.2019.1645549