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GM2-Gangliosidosis, AB Variant: Clinical, Ophthalmological, MRI, and Molecular Findings

  • Deborah RenaudEmail author
  • Michael Brodsky
Case Report
Part of the JIMD Reports book series (JIMD, volume 25)

Abstract

GM2-gangliosidosis, AB variant is a very rare form of GM2 gangliosidosis due to a deficiency of GM2 activator protein, associated with autosomal recessive mutations in GM2A. Less than ten patients, confirmed by molecular analysis, have been described in the literature.

A 12-month-old Hmong girl presented to the neurometabolic clinic for evaluation of global developmental delay, hypotonia, and cherry red spots. The parents were not known to be consanguineous. Her examination was remarkable for hypotonia with hyperreflexia and excessive startling. The head circumference was normal. An extensive neurometabolic evaluation was negative.

Developmental regression began at 14 months of age. Retinal examination at 16 months of age disclosed 4+ cherry red/black spots with “heaped up” ring of whitish infiltrate surrounding both foveae but no evidence of optic atrophy or peripheral retinal abnormalities. Repeat magnetic resonance imaging (MRI) scan at 17 months of age revealed delayed but interval myelination associated with abnormal signal intensity of the bilateral thalami presenting as T2 hyperintensity of the posterior thalami in the region of the pulvinar nuclei and T2 hypointensity in the anterior thalami. Sequencing of the GM2A gene revealed a homozygous c.160 G>T mutation, predicted to result in a premature protein termination p. Glu54*.

Keywords

Global Developmental Delay Abnormal Signal Intensity Sandhoff Disease Repeat Magnetic Resonance Imaging Anterior Thalamus 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

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Copyright information

© SSIEM and Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.Department NeurologyMayo ClinicRochesterUSA
  2. 2.Department of PediatricsMayo ClinicRochesterUSA
  3. 3.Department of OphthalmologyMayo ClinicRochesterUSA

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