Neuroradiological, neurophysiological and molecular findings in infantile Krabbe disease: two case reports

From pathological mechanisms in Krabbe disease to cutting-edge therapy: A comprehensive review

Since its initial documentation by Knud Krabbe in 1916, numerous studies have scrutinized the characteristics of Krabbe disease (KD) until the identification of the mutation in the GALC gene. In alignment with that, we investigated the natural history of KD spanning eight decades to gain a deeper understanding of the evolutionary trajectory of its mechanisms. Through our comprehensive analysis, we unearthed additional novel elements in molecular biology involving the micropathological mechanism of the disease. This review offers an updated perspective on the metabolic disorder that defines KD. Recently, extracellular vesicles (EVs), autophagy impairment, and α-synuclein have emerged as pivotal players in the neuropathological processes. EVs might serve as a cellular mechanism to avoid or alleviate the detrimental impacts of excessive toxic psychosine levels, and extracting EVs could contribute to synapse dysfunction. Autophagy impairment was found to be independent of psychosine and reliant on AKT and B-cell lymphoma 2. Additionally, α-synuclein has been recognized for inducing cellular death and dysfunction in common biological pathways. Our objective is to assess the effectiveness of advanced therapies in addressing this particular condition. While hematopoietic stem cells have been a primary treatment, its administration proves challenging, particularly in the presymptomatic phase. In this review, we have compiled information from over 10 therapy trials, comparing them based on their benefits and disadvantage.

Spontaneous Third Ventriculostomy in Krabbe Disease

INTRODUCTION

Spontaneous third ventriculostomies have been reported in relation to obstructive hydrocephalus and increased intracranial pressure and are most commonly seen as disruption of the floor of the third ventricle. Hydrocephalus has been reported in patients with Krabbe disease; however, it is clinically difficult to monitor for hydrocephalus in patients with Krabbe disease as symptoms of increased intracranial pressure may overlap with symptoms of Krabbe disease. We describe a case series of spontaneous third ventriculostomy and hydrocephalus, likely in response to increased intracranial pressure, in patients with infantile Krabbe disease.

METHODS

Brain magnetic resonance images of patients with infantile Krabbe disease were retrospectively analyzed to assess for ventricular size and presence of spontaneous third ventriculostomies. A brain atlas was used to standardize the calculation of ventricular size. Mid-sagittal, T2-weighted images around the third ventricle were assessed for spontaneous third ventriculostomies. Developmental outcomes were measured with a series of standardized and validated tests.

RESULTS

Seventy-five patients with infantile Krabbe disease were evaluated. Twelve cases of spontaneous third ventriculostomies were identified. Head circumference (SE = 8.07; P < 0.001) and average ventricular volume were greater (left: SE = 1.47, P < 0.001) in patients with spontaneous third ventriculostomies when compared with patients without spontaneous third ventriculostomies. Patients with spontaneous third ventriculostomies also had more delayed development in adaptive (difference = 0.2, P < 0.01), gross motor (difference = 0.0, P < 0.01), and fine motor (difference = 0.1, P < 0.001) function.

CONCLUSIONS

Spontaneous third ventriculostomies, likely in the context of increased intracranial pressure, were identified in patients with Krabbe disease. Although difficult to assess, our study highlights the importance of monitoring for increased intracranial pressure, which can result in spontaneous third ventriculostomies, in patients with infantile Krabbe disease.

A novel homozygous GALC variant has been associated with Krabbe disease in a consanguineous family

Krabbe disease (KD) or globoid cell leukodystrophy is an autosomal recessive lysosomal storage disorder involving the white matter of the peripheral and the central nervous systems. It is caused by a deficiency of galactocerebrosidase enzyme activity. The most common manifestation is the classical early onset KD that leads to patient's loss before the age of 2. Herein, we report the evaluation of a consanguineous family with three affected children manifesting severe neurological findings that ended with death before the age of 2, in an attempt to provide genetic diagnosis to the family. One of the children underwent detailed physical and neurological examinations, including brain magnetic resonance imaging (MRI) and scalp electroencephalography (EEG) evaluations. GALC genetic testing on this child enabled identification of a novel homozygous variant (NM_000153.3: c.1394C>T; p.(Thr465Ile)), which confirmed diagnosis as KD. Familial segregation of this variant was performed by PCR amplification and Sanger sequencing that revealed the parents as heterozygous carriers. We believe this novel GALC variant will not only help in genetic counseling to this family but will also aid in identification of future KD cases.

Krabbe Disease: Report of a Rare Lipid Storage and Neurodegenerative Disorder

Krabbe disease is a rare (one in 100,000 births) autosomal recessive condition, usually noticed among children. It causes sphingolipidosis (dysfunctional metabolism of sphingolipids) and leads to fatal degenerative changes affecting the myelin sheath of the nervous system. We report a case of a six-year-old male child who presented with symptoms of muscle spasticity and irritability. Diagnosis of this disease can only be made with clinical suspicion. Laboratory diagnosis includes brain magnetic resonance imaging (MRI), magnetic resonance (MR) spectroscopy, biochemical analysis of cerebrospinal fluid, and genetic analysis for detecting mutation in genes coding for galactosyl cerebroside (GALC). We report a case of late infantile Krabbe disease.