Annals of Movement Disorders

CASE REPORTS
Year
: 2019  |  Volume : 2  |  Issue : 3  |  Page : 134--135

Wishbone pattern of iron accumulation: A pathognomonic sign of type III GM1 gangliosidosis


Shweta Prasad1, Lulup K Sahoo2, Jitender Saini3, Pramod K Pal2,  
1 Department of Clinical Neuroscience, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India; Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
2 Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
3 Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India

Correspondence Address:
Dr. Pramod K Pal
Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru 560029, Karnataka.
India

Abstract

Type III GM1 gangliosidosis is the adult or chronic variant of a lysosomal storage disorder, which occurs secondary to deficiency of β-galactosidase. The wishbone pattern of iron deposition which involves the medial and latter parts of the globus pallidus is pathognomonic of this disease. The diagnosis of type III GM1 gangliosidosis should be considered in patient with young onset, progressive generalized dystonia with prominent facial dystonia, and a wishbone pattern of iron deposition.



How to cite this article:
Prasad S, Sahoo LK, Saini J, Pal PK. Wishbone pattern of iron accumulation: A pathognomonic sign of type III GM1 gangliosidosis.Ann Mov Disord 2019;2:134-135


How to cite this URL:
Prasad S, Sahoo LK, Saini J, Pal PK. Wishbone pattern of iron accumulation: A pathognomonic sign of type III GM1 gangliosidosis. Ann Mov Disord [serial online] 2019 [cited 2023 Jan 27 ];2:134-135
Available from: https://www.aomd.in/text.asp?2019/2/3/134/272282


Full Text



 Introduction



GM1 gangliosidosis is a lysosomal storage disorder, which occurs secondary to deficiency of β-galactosidase.[1] There are three distinct clinical phenotypes of GM1 gangliosidosis, of which, type III, that is, the adult or chronic variant presents as a progressive extrapyramidal disorder, particularly dystonia.[2]

A 23-year-old woman, born of a second-degree consanguineous parentage, with no abnormal developmental history or significant family history, presented with a 17-year history of progressive orolingual, cervical, and limb dystonia. Symptoms initially started with dystonic posturing of the left leg and gradually progressed to involve other regions. On examination, she had a staring look, dysarthric speech, facial dystonia (involving the zygomaticus, perioral, and frontalis muscles), and frequent facial twitching (involving the lips and periorbital muscles). There was no Kayser-Fleischer ring, and fundus was normal. Extraocular muscle movements were abnormal—vertical supranuclear gaze palsy, jerky pursuits, and slow saccades. She had significant rigidity and generalized dystonia with lingual dystonia, retrocollis, left laterocollis, truncal dystonia, and dystonia of both upper and lower limbs. Sensory examination was normal, and no organomegaly was reported.

Magnetic resonance imaging of brain showed mineralization of bilateral globus pallidus, bilateral posterior putaminal volume loss, and hyperintensity in T2-weighted Fluid attenuation inversion recovery images [Figure 1]A. Susceptibility weighted images revealed a characteristic wishbone pattern of iron deposition,[3] involving the medial and lateral parts of the globus pallidus [Figure 1]B. The wishbone pattern of iron deposition is considered to be a pathognomonic sign in type III GM1 gangliosidosis,[4] wherein iron deposition occurs due to defective intralysosomal recycling.[1] Mineralization of the globus pallidus may suggest neurodegeneration with brain iron accumulation; however, the characteristic pattern of deposition, in addition to putaminal changes should raise a suspicion of type III GM1 gangliosidosis. In the present case, diagnosis was confirmed by clinical exome sequencing, which revealed compound heterozygous mutations in the GLB1 gene.{Figure 1}

Although rare, a diagnosis of type III GM1 gangliosidosis should be considered in a patient with young onset, progressive generalized dystonia with prominent facial dystonia, and a wishbone pattern of iron deposition.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

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