Hereditary Diffuse Leukoencephalopathy Research Articles

Deep White Matter Lesions with Persistent Diffusion Restriction on MRI as a Diagnostic Clue: Neuroimaging of a Turkish Family with Hereditary Diffuse Leukoencephalopathy with Spheroids and Literature Review.

Background:Hereditary diffuse leukoencephalopathy with spheroids (HDLS), first described in 1984 is a rare disorder. Generally, it presents at adulthood with dementia, motor impairment, extrapyramidal abnormalities, and epilepsy. Definitive diagnosis is made by brain biopsy. Neuroimaging studies have revealed confluent white matter lesions predominantly in the frontal lobes, corpus callosum, and corticospinal tracts on conventional magnetic resonance imaging. Only a few reports showed diffusion restriction in the cerebral white matter; furthermore, rarer reports emphasized persistent foci of diffusion restriction as a diagnostic imaging marker.Objective:Herein, we have aimed to illustrate the first biopsy-proven Turkish HDLS pedigree consisting of 18 persons in 3 generations which contained 4 affected individuals.Materials and Methods:Four individuals in the pedigree of HDLS [two affected patients (patient III-1 and patient III-2) and two unaffected individuals (patient II-4 and patient III-5)] were investigated with conventional MRI and Diffusion-weighted imaging (DWI) using 1.5 Tesla (T) scanner. All four individuals were evaluated via neurological examinations and Mini-Mental State Examination. Brain biopsy study was performed on patient III-2. Finally, an extensive literature review involving pathology investigations and neuroimaging studies of HDLS patients was conducted.Results:DWIs of two investigated patients showed deep white matter lesions with persistent diffusion restriction. Computed tomography imaging showed punctate mineralization in the lesions. Biopsy specimens of patient III-2 demonstrated axonal spheroids which were typical for HDLS.Conclusions:Via the presentation of our pedigree and literature review, we suggest HDSL as a first-line differential diagnosis in patients with undiagnosed adult-onset familial leukoencephalopathy, in particular, those with MRI lesions of frontal white matter and centrum semiovale associated with foci of diffusion restriction and mineralization. Finally, we think that the persistence of the diffusion restriction in deep white matter lesions should be kept in mind as a crucial neuroimaging sign for HDLS.

Clinical features and genetic characteristics of hereditary diffuse leukoencephalopathy with spheroids due to CSF1R mutation: a case report and literature review.

Hereditary diffuse leukoencephalopathy with spheroid (HDLS) is an autosomal dominant white matter disease characterized by adult-onset cognitive impairment, behavioral or emotional changes, paresis, Parkinsonism, and seizures. Mutations in the gene encoding colony-stimulating factor 1 receptor (CSF1R) have been identified as the cause of HDLS. Detail medical history, clinical features and brain imaging of a patient with adult-onset leukoencephalopathy, cognitive impairment and motor dysfunction was reviewed and next generation sequencing was performed. An extensive literature research was then performed to identify all patients with HDLS previously reported. The clinical characteristics, brain imaging and genetic features of patients with HDLS were reviewed. A novel CSF1R mutation, c.1952G>A p.G651E was identified in the patient. Extensive review showed that HDLS typically presents with broad phenotypic variability. The most common symptoms of HDLS were cognitive impairment, followed by psychiatric symptoms, Parkinsonism, gait disorder, and dysphagia. The most common brain imaging findings of HDLS were bilateral white matter lesion, mostly around the ventricles, frontal lobe, and parietal lobe. Calcifications in white matter on CT, cerebral atrophy and thinning of corpus callosum were also common features. Although HDLS demonstrates an autosomal dominant pattern, sporadic cases are not uncommon. Early recognition of clinical and neuroradiographical characteristics of HDLS is key for the correct diagnosis of the disease.

Clinicopathologic characterization and abnormal autophagy of CSF1R-related leukoencephalopathy

BackgroundCSF1R-related leukoencephalopathy, also known as hereditary diffuse leukoencephalopathy with spheroids (HDLS), is a rare white-matter encephalopathy characterized by motor and neuropsychiatric symptoms due to colony-stimulating factor 1 receptor (CSF1R) gene mutation. Few of CSF1R mutations have been functionally testified and the pathogenesis remains unknown.MethodsIn order to investigate clinical and pathological characteristics of patients with CSF1R-related leukoencephalopathy and explore the potential impact of CSF1R mutations, we analyzed clinical manifestations of 15 patients from 10 unrelated families and performed brain biopsy in 2 cases. Next generation sequencing was conducted for 10 probands to confirm the diagnosis. Sanger sequencing, segregation analysis and phenotypic reevaluation were utilized to substantiate findings. Functional examination of identified mutations was further explored.ResultsClinical and neuroimaging characteristics were summarized. The average age at onset was 35.9 ± 6.4 years (range 24–46 years old). Younger age of onset was observed in female than male (34.2 vs. 39.2 years). The most common initial symptoms were speech dysfunction, cognitive decline and parkinsonian symptoms. One patient also had marked peripheral neuropathy. Brain biopsy of two cases showed typical pathological changes, including myelin loss, axonal spheroids, phosphorylated neurofilament and activated macrophages. Electron microscopy disclosed increased mitochondrial vacuolation and disorganized neurofilaments in ballooned axons. A total of 7 pathogenic variants (4 novel, 3 documented) were identified with autophosphorylation deficiency, among which c.2342C > T remained partial function of autophosphorylation. Western blotting disclosed the significantly lower level of c.2026C > T (p.R676*) than wild type. The level of microtubule associated protein 1 light chain 3-II (LC3-II), a classical marker of autophagy, was significantly lower in mutants expressed cells than wild type group by western blotting and immunofluorescence staining.ConclusionsOur findings support the loss-of-function and haploinsufficiency hypothesis in pathogenesis. Autophagy abnormality may play a role in the disease. Repairing or promoting the phosphorylation level of mutant CSF1R may shed light on therapeutic targets in the future. However, whether peripheral polyneuropathy potentially belongs to CSF1R-related spectrum deserves further study with longer follow-up and more patients enrolled.Trial registrationChiCTR, ChiCTR1800015295. Registered 21 March 2018.

An AARS variant as the likely cause of Swedish type hereditary diffuse leukoencephalopathy with spheroids

Swedish type Hereditary Diffuse Leukoencephalopathy with Spheroids (HDLS-S) is a severe adult-onset leukoencephalopathy with the histopathological hallmark of neuraxonal degeneration with spheroids, described in a large family with a dominant inheritance pattern. The initial stage of the disease is dominated by frontal lobe symptoms that develop into a rapidly advancing encephalopathy with pyramidal, deep sensory, extrapyramidal and optic tract symptoms. Median survival is less than 10 years. Recently, pathogenic mutations in CSF1R were reported in a clinically and histologically similar leukoencephalopathy segregating in several families. Still, the cause of HDLS-S remained elusive since its initial description in 1984, with no CSF1R mutations identified in the family. Here we update the original findings associated with HDLS-S after a systematic and recent assessment of several family members. We also report the results from exome sequencing analyses indicating the p.Cys152Phe variant in the alanyl tRNA synthetase (AARS) gene as the probable cause of this disease. The variant affects an amino acid located in the aminoacylation domain of the protein and does not cause differences in splicing or expression in the brain. Brain pathology in one case after 10 years of disease duration showed the end stage of the disease to be characterized by widespread liquefaction of the white matter leaving only some macrophages and glial cells behind the centrifugally progressing front. These results point to AARS as a candidate gene for rapidly progressing adult-onset CSF1R-negative leukoencephalopathies.

Genetic Factors of Cerebral Small Vessel Disease and Their Potential Clinical Outcome.

Cerebral small vessel diseases (SVD) have been causally correlated with ischemic strokes, leading to cognitive decline and vascular dementia. Neuroimaging and molecular genetic tests could improve diagnostic accuracy in patients with potential SVD. Several types of monogenic, hereditary cerebral SVD have been identified: cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL), cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), cathepsin A-related arteriopathy with strokes and leukoencephalopathy (CARASAL), hereditary diffuse leukoencephalopathy with spheroids (HDLS), COL4A1/2-related disorders, and Fabry disease. These disorders can be distinguished based on their genetics, pathological and imaging findings, clinical manifestation, and diagnosis. Genetic studies of sporadic cerebral SVD have demonstrated a high degree of heritability, particularly among patients with young-onset stroke. Common genetic variants in monogenic disease may contribute to pathological progress in several cerebral SVD subtypes, revealing distinct genetic mechanisms in different subtype of SVD. Hence, genetic molecular analysis should be used as the final gold standard of diagnosis. The purpose of this review was to summarize the recent discoveries made surrounding the genetics of cerebral SVD and their clinical significance, to provide new insights into the pathogenesis of cerebral SVD, and to highlight the possible convergence of disease mechanisms in monogenic and sporadic cerebral SVD.

P1-14-04. Pyramidal tract evaluation by transcranial magnetic stimulation in hereditary diffuse leukoencephalopathy with axonal spheroids (HDLS)

P1-14-04. Pyramidal tract evaluation by transcranial magnetic stimulation in hereditary diffuse leukoencephalopathy with axonal spheroids (HDLS)

P2‐277: RAPID PROGRESSIVE DEMENTIA IN HDLS WITH A NOVEL CSF1R MUTATION

Hereditary diffuse leukoencephalopathy with axonal spheroids and pigmented glia (HDLS) is a hereditary leukodystrophy whose main clinical manifestations include parkinsonism, spasticity, and ataxia. A 39-year old man gradually developed a decline in cognitive functions with spastic gait and parkinsonism. The patient was initially diagnosed with a progressive variant of young-onset dementia or parkinsonism. But gait disturbances and cognitive impairment became more severe, and then the differential diagnosis was made for other causes including genetic testing. Brain MRI showed fronto-temporal atrophy with hyperintense multiple small lesions in the deep cerebral white matter, and deep white matter diffusion abnormalities. The DNA analysis revealed a novel missense mutation c.2349C>A (p.Asn783Gln) of the CSF1R gene. We report a patient with rapid progression of cognitive and gait manifestations of HDLS and a novel CSF1R mutation. Hereditary diffuse leukoencephalopathy with axonal spheroids should be included in the differential diagnosis of young-onset progressive dementia and gait disturbance.

P2‐288: TWO NOVEL MUTATIONS IN CSF1R CAUSING HEREDITARY DIFFUSE LEUKOENCEPHALOPATHY WITH AXONAL SPHEROIDS (HDLS)

Hereditary diffuse leukoencephalopathy with axonal spheroids (HDLS) is a neurodegenerative disease presenting in midlife and associated with rapidly progressive cognitive, behavioral and motor symptoms. HDLS results from mutations in the CSF1R gene and is inherited in an autosomal dominant pattern. We describe the clinical and neuroimaging features of two cases of HDLS evaluated at our medical center.and compare them with previously reported cases. Both patients had clinical genetic testing done revealing mutations in CSF1R. Patient 1 is a 46 year old woman who initially presented with gait changes and dysarthria, with rapid progression of bulbar and cognitive symptoms over 18 months, and was found to have a mutation in exon 19, c.2519C>G (p.Ser840Cys). Patient 2 is a 56 year old man presenting with 3 years of depression and memory problems without significant motor symptoms in the context of a family history of early onset dementia syndrome in his mother and prior diagnosis of HDLS in his maternal aunt; he was also found to have a mutation in exon 19, c.2480T>A (p.Ile827Asn). Both patients demonstrated extensive white matter hyperintensities and thinning of the corpus callosum on their MRIs with Patient 1 having cavitary lesions. Both mutations are located in the tyrosine kinase domain of the protein at or near the location of previously described mutations. Both mutations are predicted to be probably damaging by Polyphen with a score of 1.0. To our knowledge, these are the first reported cases of HDLS associated with these mutations. As has been described in the literature, the female patient had a younger age of onset than the male. Clinicians should be aware of the diversity of clinical presentations of HDLS and consider genetic testing for atypical dementia syndromes associated with significant white matter changes.

Bi-allelic CSF1R Mutations Cause Skeletal Dysplasia of Dysosteosclerosis-Pyle Disease Spectrum and Degenerative Encephalopathy with Brain Malformation

Colony stimulating factor 1 receptor (CSF1R) plays key roles in regulating development and function of the monocyte/macrophage lineage, including microglia and osteoclasts. Mono-allelic mutations of CSF1R are known to cause hereditary diffuse leukoencephalopathy with spheroids (HDLS), an adult-onset progressive neurodegenerative disorder. Here, we report seven affected individuals from three unrelated families who had bi-allelic CSF1R mutations. In addition to early-onset HDLS-like neurological disorders, they had brain malformations and skeletal dysplasia compatible to dysosteosclerosis (DOS) or Pyle disease. We identified five CSF1R mutations that were homozygous or compound heterozygous in these affected individuals. Two of them were deep intronic mutations resulting in abnormal inclusion of intron sequences in the mRNA. Compared with Csf1r-null mice, the skeletal and neural phenotypes of the affected individuals appeared milder and variable, suggesting that at least one of the mutations in each affected individual is hypomorphic. Our results characterized a unique human skeletal phenotype caused by CSF1R deficiency and implied that bi-allelic CSF1R mutations cause a spectrum of neurological and skeletal disorders, probably depending on the residual CSF1R function.

Discriminative clinical and neuroimaging features of motor-predominant hereditary diffuse leukoencephalopathy with axonal spheroids and primary progressive multiple sclerosis: A preliminary cross-sectional study

BackgroundHereditary diffuse leukoencephalopathy with axonal spheroids (HDLS) is a rare autosomal-dominant white matter disease, typically characterized by juvenile cognitive decline and frontoparietal white matter lesions. A portion of HDLS patients exhibit preferential motor dysfunctions as their initial symptoms, mimicking multiple sclerosis (MS). However, there is no study comparing this phenotype of HDLS and primary progressive multiple sclerosis (PPMS), which greatly resemble each other. This is the first preliminary study to clarify the clinical and neuroimaging features of motor-predominant HDLS, and compare it with PPMS, using cases whose colony stimulating factor 1 receptor (CSF1R) were sequenced. MethodsClinical and radiological data from Japanese patients at the Department of Neurology, Kyushu University Hospital, Fukuoka, Japan, were evaluated retrospectively and cross-sectionally. Twenty-nine brain and 18 spinal cord magnetic resonance imaging (MRI) scans from four motor-predominant HDLS patients with CSF1R mutations and 15 PPMS patients without CSF1R mutations, were evaluated using an HDLS MRI scoring system. ResultsTwo patients with HDLS were initially diagnosed with MS and received immunotherapy. Clinically, motor-predominant HDLS and PPMS patients resembled each other in onset age and disability. However, motor-predominant HDLS patients had a significantly higher frequency of frontal release signs, lower positivity rates of oligoclonal IgG bands (OCB), and lower IgG index values. Total HDLS MRI scores, total white matter lesions (WMLs), and brain atrophy were similar between the diseases. However, motor-predominant HDLS patients had more marked atrophy of the corpus callosum (CC) body, more WMLs in the deep and subcortical regions of the frontoparietal lobes, fewer WMLs in the occipitotemporal periventricular regions, and more restricted diffusivity lesions on MRI than PPMS patients. There was a stronger association between disease duration and CC index in HDLS, suggesting more rapid progression compared with PPMS. ConclusionsMotor-predominant HDLS has characteristic frequent frontal release signs, normal findings for OCB and the IgG index, severe CC body atrophy, abundant deep and subcortical WMLs in the frontoparietal lobes, subtle occipitotemporal lobe periventricular WMLs, and more restricted diffusivity lesions on MRI. Although the present study was limited by the small number of HDLS cases, we propose that immunotherapy should be avoided in such cases.

Experience of repetitive transcranial magnetic stimulation in severe dementia with hereditary diffuse leukoencephalopathy with axonal spheroid

Background: Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique, and it is applying to various diseases including dementia for improving neural circuit integrity and activity. Although there were several studies reported some positive cognitive effects of rTMS in AD, there were few studies about rTMS effects in other types of dementia patient. We report an experience of repetitive transcranial magnetic stimulation in severe dementia with hereditary diffuse leukoencephalopathy with axonal spheroid (HDLS).

CSF1R-related leukoencephalopathy: A major player in primary microgliopathies.

Since the discovery of CSF1R gene mutations in families with hereditary diffuse leukoencephalopathy with spheroids in 2012, more than 70 different mutations have been identified around the world. Through the analyses of mutation carriers, CSF1R-related leukoencephalopathy has been distinctly characterized clinically, radiologically, and pathologically. Typically, patients present with frontotemporal dementia-like phenotype in their 40s-50s, accompanied by motor symptoms, including pyramidal and extrapyramidal signs. Women tend to develop the clinical symptoms at a younger age than men. On brain imaging, in addition to white matter abnormalities, thinning of the corpus callosum, diffusion-restricted lesions in the white matter, and brain calcifications are hallmarks. Primary axonopathy followed by demyelination was suggested by pathology. Haploinsufficiency of colony-stimulating factor-1 receptor (CSF1R) is evident in a patient with a frameshift mutation, facilitating the establishment of Csf1r haploinsufficient mouse model. These mice develop clinical, radiologic, and pathologic phenotypes consistent with those of human patients with CSF1R mutations. In vitro, perturbation of CSF1R signaling is shown in cultured cells expressing mutant CSF1R. However, the underlying mechanisms by which CSF1R mutations selectively lead to white matter degeneration remains to be elucidated. Given that CSF1R mainly expresses in microglia, CSF1R-related leukoencephalopathy is representative of primary microgliopathies, of which microglia have a pivotal and primary role in pathogenesis. In this review, we address the current knowledge of CSF1R-related leukoencephalopathy and discuss the putative pathophysiology, with a focus on microglia, as well as future research directions.

Mendelian adult-onset leukodystrophy genes in Alzheimer's disease: critical influence of CSF1R and NOTCH3

Mendelian adult-onset leukodystrophies are a spectrum of rare inherited progressive neurodegenerative disorders affecting the white matter of the central nervous system. Among these, cerebral autosomal dominant and recessive arteriopathy with subcortical infarcts and leukoencephalopathy, cerebroretinal vasculopathy, metachromatic leukodystrophy, hereditary diffuse leukoencephalopathy with spheroids, and vanishing white matter disease present with rapidly progressive dementia as dominant feature and are caused by mutations in NOTCH3, HTRA1, TREX1, ARSA, CSF1R, EIF2B1, EIF2B2, EIF2B3, EIF2B4, and EIF2B5, respectively. Given the rare incidence of these disorders and the lack of unequivocally diagnostic features, leukodystrophies are frequently misdiagnosed with common sporadic dementing diseases such as Alzheimer's disease (AD), raising the question of whether these overlapping phenotypes may be explained by shared genetic risk factors. To investigate this intriguing hypothesis, we have combined gene expression analysis (1) in 6 different AD mouse strains (APPPS1, HOTASTPM, HETASTPM, TPM, TAS10, and TAU) at 5 different developmental stages (embryo [E15], 2, 4, 8, and 18 months), (2) in APPPS1 primary cortical neurons under stress conditions (oxygen-glucose deprivation) and single-variant–based and single-gene–based (c-alpha test and sequence kernel association test (SKAT)) genetic screening in a cohort composed of 332 Caucasian late-onset AD patients and 676 Caucasian elderly controls. Csf1r was significantly overexpressed (log2FC > 1, adj. p-value < 0.05) in the cortex and hippocampus of aged HOTASTPM mice with extensive Aβ dense-core plaque pathology. We identified 3 likely pathogenic mutations in CSF1R TK domain (p.L868R, p.Q691H, and p.H703Y) in our discovery and validation cohort, composed of 465 AD and mild cognitive impairment (MCI) Caucasian patients from the United Kingdom. Moreover, NOTCH3 was a significant hit in the c-alpha test (adj p-value = 0.01). Adult-onset Mendelian leukodystrophy genes are not common factors implicated in AD. Nevertheless, our study suggests a potential pathogenic link between NOTCH3, CSF1R, and sporadic late-onset AD, which warrants further investigation.

Adulthood leukodystrophies.

The leukodystrophies are a group of inherited white matter disorders with a heterogeneous genetic background, considerable phenotypic variability and disease onset at all ages. This Review focuses on leukodystrophies with major prevalence or primary onset in adulthood. We summarize 20 leukodystrophies with adult presentations, providing information on the underlying genetic mutations and on biochemical assays that aid diagnosis, where available. Definitions, clinical characteristics, age of onset, MRI findings and treatment options are all described, providing a comprehensive overview of the current knowledge of the various adulthood leukodystrophies. We highlight the distinction between adult-onset leukodystrophies and other inherited disorders with white matter involvement, and we propose a diagnostic pathway for timely recognition of adulthood leukodystrophies in a routine clinical setting. In addition, we provide detailed clinical information on selected adult-onset leukodystrophies, including X-linked adrenoleukodystrophy, metachromatic leukodystrophy, cerebrotendinous xanthomatosis, hereditary diffuse leukoencephalopathy with axonal spheroids, autosomal dominant adult-onset demyelinating leukodystrophy, adult polyglucosan body disease, and leukoencephalopathy with vanishing white matter. Ultimately, this Review aims to provide helpful suggestions to identify treatable adulthood leukodystrophies at an early stage in the disease course.

Characteristic microglial features in patients with hereditary diffuse leukoencephalopathy with spheroids caused by mutations of the gene encoding the colony stimulating factor-1 receptor

Background: Hereditary diffuse leukoencephalopathy with spheroids (HDLS) is an autosomal-dominant dementing disorder. A gene encoding the colony stimulating factor-1 receptor (CSF-1R) has been identified as the causative gene of HDLS. CSF-1R is a crucial regulator of mononuclear phagocytic cells, and expressed predominantly in microglia in CNS.

Impairment of migration related molecule expression on peripheral blood monocytes in patients with hereditary diffuse leukoencephalopathy with spheroids

Impairment of migration related molecule expression on peripheral blood monocytes in patients with hereditary diffuse leukoencephalopathy with spheroids

Identification and functional assay of novel missense mutations of CSF1R in patients with HDLS/ALSP

Background: Hereditary diffuse leukoencephalopathy with spheroids (HDLS)/Adult-onset Leukoencephalopathy with Axonal Spheroids and Pigmented Glia (ALSP) is an adult-onset leukoencephalopathy with variable clinical presentations. Colony stimulating factor 1 receptor (CSF1R) has been identified as the causative gene of HDLS/ALSP. To date, more than 50 pathological mutations in CSF1R have been identified.

An autopsied case with novel mutated hereditary diffuse leukoencephalopathy with spheroid (HDLS)

An autopsied case with novel mutated hereditary diffuse leukoencephalopathy with spheroid (HDLS)

Adult onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) and Nasu-Hakola disease: lesion staging and dynamic changes of axons and microglial subsets.

The brains of 10 Japanese patients with adult onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) encompassing hereditary diffuse leukoencephalopathy with axonal spheroids (HDLS) and pigmentary orthochromatic leukodystrophy (POLD) and eight Japanese patients with Nasu-Hakola disease (N-HD) and five age-matched Japanese controls were examined neuropathologically with special reference to lesion staging and dynamic changes of microglial subsets. In both diseases, the pathognomonic neuropathological features included spherically swollen axons (spheroids and globules), axon loss and changes of microglia in the white matter. In ALSP, four lesion stages based on the degree of axon loss were discernible: Stage I, patchy axon loss in the cerebral white matter without atrophy; Stage II, large patchy areas of axon loss with slight atrophy of the cerebral white matter and slight dilatation of the lateral ventricles; Stage III, extensive axon loss in the cerebral white matter and dilatation of the lateral and third ventricles without remarkable axon loss in the brainstem and cerebellum; Stage IV, devastated cerebral white matter with marked dilatation of the ventricles and axon loss in the brainstem and/or cerebellum. Internal capsule and pontine base were relatively well preserved in the N-HD, even at Stage IV, and the swollen axons were larger with a higher density in the ALSP. Microglial cells immunopositive for CD68, CD163 or CD204 were far more obvious in ALSP, than in N-HD, and the shape and density of the cells changed in each stage. With progression of the stage, clinical symptoms became worse to apathetic state, and epilepsy was frequently observed in patients at Stages III and IV in both diseases. From these findings, it is concluded that (i) shape, density and subsets of microglia change dynamically along the passage of stages and (ii) increase of IBA-1-, CD68-, CD163- and CD204-immunopositive cells precedes loss of axons in ALSP.

Hereditary Diffuse Leukoencephalopathy with Spheroids (HDLS): Clinical Characteristics and Pathomechanistic Insights

Hereditary diffuse leukoencephalopathy with spheroids (HDLS) is a rare autosomal dominant disease characterized by neuroaxonal swellings (spheroids) within cerebral white matter. Patients with HDLS show variable symptoms, and have mutations in the protein kinase domain of the colony-stimulating factor 1 receptor (CSF1-R) gene. Currently, more than 50 pathogenic CSF1-R mutations have been reported in patients with HDLS. This manuscript aimed to essentially review clinical characteristics and molecular mechanisms underlying HDLS pathogenesis.